Apparatuses and methods for negative pressure wound therapy

ABSTRACT

Disclosed herein are several embodiments of a negative pressure appliance and methods of using the same in the treatment of wounds. Some embodiments are directed to improved fluidic connectors or suction adapters for connecting to a wound site, for example using softer, kink-free conformable suction adapters.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 15/681,165, filed on Aug. 18, 2017, which is a continuation ofU.S. patent application Ser. No. 15/256,349, filed on Sep. 2, 2016, nowU.S. Pat. No. 9,974,695, which is a continuation of U.S. patentapplication Ser. No. 15/198,690, filed on Jun. 30, 2016, now U.S. Pat.No. 9,999,547, which is a continuation of U.S. patent application Ser.No. 15/018,724, filed on Feb. 8, 2016, now U.S. Pat. No. 9,642,750,which is a continuation of U.S. patent application Ser. No. 14/267,636,filed on May 1, 2014, now U.S. Pat. No. 9,327,065, which is acontinuation of U.S. patent application Ser. No. 13/381,885, filed onDec. 30, 2011, now U.S. Pat. No. 8,801,685 which is a national phaseapplication under 35 U.S.C. § 371 of International Application No.PCT/US2010/061938, filed on Dec. 22, 2010, which claims the benefit ofU.S. Provisional Application No. 61/289,358, filed Dec. 22, 2009, U.S.Provisional Application No. 61/332,440, filed May 7, 2010, and U.S.Provisional Application No. 61/369,008, filed Jul. 29, 2010, theentirety of each of which is hereby incorporated by reference.

FIELD OF THE INVENTION

Embodiments of the present invention relate generally to the treatmentof wounds using negative pressure wound therapy, and more specificallyto an improved apparatus and method thereof.

BACKGROUND OF THE INVENTION

The treatment of open or chronic wounds that are too large tospontaneously close or otherwise fail to heal by means of applyingnegative pressure to the site of the wound is well known in the art.Negative pressure wound treatment systems currently known in the artcommonly involve placing a cover that is impermeable to liquids over thewound, using various means to seal the cover to the tissue of thepatient surrounding the wound, and connecting a source of negativepressure (such as a vacuum pump) to the cover in a manner so that anarea of negative pressure is created under the cover in the area of thewound.

SUMMARY OF THE INVENTION

Embodiments of the invention disclosed herein are directed to a negativepressure appliance and methods of treatment using a negative pressureappliance, and may be useful in the treatment of wounds using negativepressure.

Certain embodiments of the invention employ fluidic connectors and/orsuction adapters for connecting a source of negative pressure to adressing positioned over a wound site. These fluidic connectors and/orsuction adapters offer advantages over the prior art. For example andfor illustrative purposes only, some of the embodiments may offer asofter, kink-free fluidic connector for connecting a wound site to asource of negative pressure for treatment. Such a fluidic connectorand/or suction adapter is faster to apply, requiring fewer stepscompared to prior art connectors, and offers greater patient comfort andsafety by being soft and conformable, thereby avoiding pressure ulcersand other complications caused by harder connectors.

Certain embodiments provide for a negative pressure wound treatmentsystem comprising a wound packing material configured to be positionedat a wound, a flexible drape configured to be positioned over the woundand wound packing material and sealed to the skin surrounding the wound,and which further comprises a conduit configured to deliver negativepressure to the wound through an aperture in the drape and through thewound packing material to the wound. Such embodiments further comprise aflexible suction adapter configured to surround the aperture and connectthe conduit to the flexible drape and for transmitting negative pressurefrom the conduit through the aperture.

In one embodiment, a negative pressure wound treatment system isprovided comprising a flexible drape configured to be positioned over awound and sealed to skin surrounding the wound. A conduit is configuredto deliver negative pressure to the wound, wherein negative pressure isdelivered through an aperture in the drape. A flexible suction adapteris configured to surround the aperture and connect the conduit to theflexible drape, the flexible suction adapter comprising upper and lowerlayers forming an elongate interior channel having a proximal end and adistal end, the proximal end configured for fluid communication with theconduit and the lower layer including at least one aperture forcommunicating with the aperture in the drape. An elongated foam spaceris within the interior channel extending between the proximal end andthe distal end.

In another embodiment, a negative pressure wound treatment systemcomprises a flexible drape configured to be positioned over a wound andsealed to skin surrounding the wound. The flexible drape defines anelongate channel extending between upper and lower portions of theflexible drape, wherein the channel extends from an edge of the flexibledrape to an interior portion thereof. The lower portion of the flexibledrape includes at least one aperture in communication with the elongatechannel for transmitting negative pressure through the channel andthrough the aperture. A conduit is configured to deliver negativepressure to the wound, wherein the conduit is connected to the channelto deliver negative pressure through the channel and the at least oneaperture in the lower layer.

In yet another embodiment, a negative pressure wound treatment systemcomprises a bridge with top, bottom, and intermediate layers sandwichingtop and bottom fluid channels, wherein the top channel comprises an airleak, and the bottom channel is connected to a source of negativepressure suitable for drawing exudates from a wound site. The bridge isattached to an applicator portion including at least one aperture andsuitable for placement over a wound site, and may also include avisualization window for visualization of the wound site.

Methods of treating wounds with negative pressure are also described. Amethod of treating a wound with negative pressure may include applying aflexible drape over a wound site, applying a flexible suction adapterover the wound site, where the flexible adapter comprises an applicatorand bridge portion provided with an air leak. The suction adapter isthen connected to a source of negative pressure, and negative pressureis applied to the wound until it has reached a desired level of healing.

Also disclosed herein are embodiments of an apparatus for providingsuction to a wound site comprising a top and bottom layer constructedfrom a liquid-impermeable material with a 3D knitted or 3D fabricmaterial located between these top and bottom layers. An aperture in thebottom layer is in fluid communication with the 3D knitted or 3D fabricmaterial. An elongate channel extends between the top and bottom layerscontaining the 3D knitted or 3D fabric material. The top layer, bottomlayer, and 3D knitted or 3D fabric material include enlarged distal endswith the elongate channel extending in a proximal direction away fromthe enlarged distal ends.

In some embodiments, the elongate channel comprises a lower fluidpassage, and the apparatus comprises an upper fluid passage disposedabove and separate from the 3D knitted or 3D fabric material that isconnected to an air leak. In some cases, the upper fluid passage maycontain foam or another compliant spacer material. In other embodiments,an air leak communicates with a wound site through a conduit extendingin a proximal direction away form the enlarged distal ends and may insome cases include a looped portion. The enlarged ends of the top andbottom layers may be rectangular or square, or may form a teardropshape, and the 3D knitted or 3D fabric material may have a circularenlarged end. The 3D knitted or 3D fabric material may also be in fluidcommunication with a source of negative pressure, such as a pump. Thebottom layer may be configured to be attached to a drape, or may beattached to an applicator. The bottom layer may also comprise anadhesive disposed on its wound-facing side, and can in some cases beprovided with multiple apertures. In some embodiments, the 3D knitted or3D fabric material may be in fluid communication with a dual lumen tubethat incorporates an air leak at a proximal portion thereof. The airleak may in some cases comprise a plurality of discrete air channels,and may be located on the enlarged distal end of the top layer. The 3Dknitted or 3D fabric material can be provided with a flattened distalend.

Embodiments of systems for the treatment of wounds using negativepressure using embodiments of the suction adapters disclosed above arealso disclosed. These systems can comprise a suction adapter asdescribed previously, a flexible drape configured to be positioned overa wound and sealed to the skin surrounding the wound, and where thesuction adapter is configured to be attached to the drape so as tosurround an aperture formed in the drape. A vacuum pump may be connectedby at least one conduit to the suction adapter.

In another embodiment of a suction adapter, this adapter has anapplicator with an upper and lower surface, with the upper surfaceconnected to the distal end of a bridge. The bridge has a proximal endand a distal end, and has an upper fluid passage connected to an airleak and a lower fluid passage in fluid communication with a source ofnegative pressure, with the lower fluid passage comprising a 3D knittedor 3D fabric material.

In some embodiments of the suction adapter, the upper fluid passage maycomprise foam. The bridge portion may further comprise a top layer, abottom layer and an intermediate layer, each of the layers havingproximal ends and distal ends and elongate portions extendingtherebetween, where the upper fluid passage extends between the top andintermediate layers, and the lower fluid passage extends between theintermediate and bottom layers. The distal end of the bridge may alsohave an enlarged shape. The air leak may be disposed at the proximal endof the bridge. The 3D knitted or 3D fabric material may include a topknitted layer, a bottom knitted layer, and a middle area with verticallyextending fibers, and may be approximately 1.5 to 6 mm thick. The 3Dknitted or 3D fabric material may be constructed so as to resistcompression to less than half its original thickness when subjected to aload of 15 psi.

The suction adapter embodiments above may be used in embodiments of anegative pressure wound treatment system comprising a flexible drapeconfigured to be positioned over a wound and sealed to the skinsurrounding the wound, and where the suction adapter is configured to beattached to the drape so as to surround at least one aperture formed inthe drape. A vacuum pump is preferably connected by at least one conduitto the suction adapter.

Further embodiments of negative pressure wound treatment systemsdescribed herein may comprise a flexible drape configured to bepositioned over a wound and sealed to skin surrounding the wound, aconduit configured to deliver negative pressure to the wound, whereinnegative pressure is delivered through an aperture in the drape, and aflexible suction adapter configured to surround the aperture on thedrape and connect the conduit to the flexible drape. The flexiblesuction adapter can comprise upper and lower layers forming an elongateinterior channel with proximal and distal ends, where the proximal endis configured to communicate fluidically with the conduit and whereinthe lower layer has at least one aperture for communicating with theaperture in the drape. An elongated spacer extending between theproximal and distal ends may also be placed within the interior channel.

In some embodiments, the elongated spacer may become progressivelylarger toward the distal end. The interior channel may incorporate alooped portion that extends toward and away from the at least oneaperture in the lower layer, and the spacer may be configured similarly.The channel in the suction adapter may also comprise an air leak, whichmay be disposed between the proximal and distal end of the channel, andmay also incorporate a filter. The lower layer of the suction adaptermay comprise more than one aperture, for example four apertures. Thewound may also be packed with a wound packing material placed under theflexible drape.

Another embodiment of a negative pressure wound treatment systemdescribed herein includes a wound packing material configured to bepositioned at a wound, a flexible drape configured to be positioned overthe wound packing material and over the wound and sealed to skinsurrounding the wound, a conduit configured to deliver negative pressureto the wound through an aperture in a drape and through the woundpacking material placed in the wound, and a flexible suction adapterconfigured to surround the aperture and connect the conduit to theflexible drape and for transmitting negative pressure from the conduitthrough the aperture.

In some embodiments, the suction adapter may be a flexible shroud havinga distal end configured to seal with the flexible drape around theaperture and a proximal end configured to seal about the conduit, wherethe conduit is configured to extend through the flexible shroud into theaperture. The suction adapter may also be a sealing disc sandwichedbetween annular upper and lower support discs, where the lower supportdisc is configured to be adhered to the flexible drape around theaperture, and the conduit is configured to extend through openings inthe sealing disc and upper and lower support discs into the aperture. Inother cases, the flexible suction adapter may be a sealing ringintegrated with the aperture in the drape, with the conduit being sizedand configured to make a sealing contact with the sealing ring. Theflexible suction adapter may also comprise upper and lower supportlayers sandwiching a looped portion of the conduit, where the lowerlayer includes at least one aperture and the conduit includes aplurality of apertures so that negative pressure can be transmittedthrough the plurality of apertures in the conduit through the at leastone aperture in the lower layer and through the aperture in the flexibledrape. The flexible suction adapter can also have upper and lowersupport layers sandwiching an elongated foam spacer, where the lowerlayer includes at least one aperture for transmitting negative pressurefrom the foam spacer to the aperture in the flexible drape, and theelongated foam spacer includes a proximal end configured to connect to adistal end of the conduit. The suction adapter can also comprise amembrane with elongate parallel channels integrated onto it andconfigured to be positioned over the flexible drape around the apertureso as to channel wound exudate. In another embodiment, the flexibledrape can define a lower layer and further comprises an upper layer thatsandwiches the flexible suction adapter between the upper and lowerlayers; the flexible suction adapter can comprise a foam spacer.

Yet another embodiment of a negative pressure wound treatment systemcomprises a flexible drape configured to be positioned over a wound andsealed to skin surrounding the wound, with the flexible drape definingan elongate channel extending between upper and lower portions of theflexible drape, and where the channel extends from an edge of theflexible drape to an interior portion of the flexible drape, the lowerportion of the flexible drape including at least one aperture incommunication with the elongate channel for transmitting negativepressure through the channel and through the aperture. A conduit isconfigured to deliver negative pressure to the wound, where the conduitis connected to the channel to deliver negative pressure through thechannel and the at least one aperture in the lower layer. In someembodiments, a foam spacer may extend into the channel, and spacercomprising bosses may also be present on in an interior portion of thechannel.

Embodiments of a suction adapter described herein can include anapplicator with an upper surface and a lower surface, a bridge with aproximal end and a distal end, where the distal end of the bridge isconnected to the upper surface of the applicator, and where the bridgecomprises a top layer, a bottom layer and an intermediate layer, each ofthe layers having proximal ends and distal ends and elongate portionsextending therebetween. A first channel layer then extends between thetop and intermediate layers, where the first channel layer has aproximal end and a distal end and an elongate portion extendingtherebetween. A second channel layer extends between the intermediateand bottom layers, where the channel layer has a proximal end and adistal end and an elongate portion extending therebetween. An air leakis disposed at the proximal end of the top layer that is configured toprovide an air path into the first channel layer.

Another embodiment described herein includes a suction adapter suitableto treat a wound site with negative pressure that includes an applicatorwith an upper surface and a lower surface, a bridge having a proximalend and a distal end, where the distal end of the bridge is connected tothe upper surface of the applicator. The bridge comprises a top layer, abottom layer and an intermediate layer, with each layer having aproximal end and a distal end and an elongate portion extendingtherebetween, a first channel layer extending between the top andintermediate layers, the first channel layer having a proximal end and adistal end and an elongate portion extending therebetween and a secondchannel layer extending between the intermediate and bottom layers, thesecond channel layer having a proximal end and a distal end and anelongate portion extending therebetween. An air leak is disposed at theproximal end of the top layer, the air leak configured to provide an airpath into the first channel layer. One of the first and second channellayers comprises foam and the other of the first and second channellayers comprising a fabric.

Methods of treating a wound with negative pressure are also disclosedherein. A method of treating a wound site with negative pressurecomprises applying a flexible drape over a wound site, applying aflexible suction adapter over an opening in the flexible drape, wherethe flexible suction adapter comprises top and bottom layers constructedfrom a liquid-impermeable material, a 3D knitted or 3D fabric materiallocated between the top and bottom layers, an aperture in the bottomlayer in fluid communication with the wound site through the opening andthe 3D knitted or 3D fabric material, and applying negative pressure tothe wound, the negative pressure being transmitted to the wound throughat least one conduit connected between the source of negative pressureand the flexible suction adapter and passing through the 3D knitted or3D fabric material through the aperture in the bottom layer and into theopening in the flexible drape.

In some embodiments, the application of negative pressure to the woundmay cause air to flow into the wound via an air leak disposed on theflexible suction adapter. The flow rate of air, may, in some embodimentsbe at least 0.08 liters/minute when negative pressure is applied to thesuction adapter, and this flow rate may be maintained while a weight isplaced on the suction adapter, for example a 4.75 kg weight. Adhesivemay be placed on the suction adapter when adhering the adapter to thedrape, or the adapter can be supplied pre-attached to a drape.Otherwise, the method above may comprise cutting an opening into thedrape. Wound contact material can also be placed into the wound siteprior to applying the drape. A similar method may transmit negativepressure to the wound through at least one conduit connected between thesource of negative pressure and the flexible suction adapter and thatpasses through the 3D knitted material into the opening in the flexibledrape.

Yet another method of treating a wound site with negative pressure isdisclosed herein. This method comprises applying a flexible drape over awound site, applying a flexible suction adapter over an opening made inthe flexible drape, the flexible suction adapter comprising anapplicator having an upper surface and a lower surface and a bridgehaving a proximal end and a distal end, and where the distal end of thebridge is connected to the upper surface of the applicator, and thebridge comprises a top layer, a bottom layer and an intermediate layer,each of the layers having proximal ends and distal ends and elongateportions extending therebetween, a first channel layer extending betweenthe top and intermediate layers, where the first channel layer has aproximal end and a distal end and an elongate portion extendingtherebetween, a second channel layer extending between the intermediateand bottom layers, the channel layer having a proximal end and a distalend and an elongate portion extending therebetween, an air leak disposedat the proximal end of the top layer configured to provide an air pathinto the first channel layer. The flexible suction adapter is connectedto a source of negative pressure, and negative pressure is applied tothe wound, the negative pressure being transmitted through the secondchannel layer and drawing in air from the air leak through the firstchannel layer.

A further method for treating a wound with negative pressure isdescribed herein. This method comprises applying a flexible drape over awound site, applying a flexible suction adapter over an opening made inthe flexible drape, connecting the flexible suction adapter to a sourceof negative pressure; and applying negative pressure to the wound, thenegative pressure being transmitted through the second channel layer anddrawing in air from the air leak through the first channel layer. Theflexible suction adapter used comprises an applicator having an uppersurface and a lower surface and a bridge having a proximal end and adistal end, the distal end of the bridge being connected to the uppersurface of the applicator. The bridge comprises a top layer, a bottomlayer and an intermediate layer, with each of the layers having proximalends and distal ends and elongate portions extending therebetween, afirst channel layer extending between the top and intermediate layers,the first channel layer having a proximal end and a distal end and anelongate portion extending therebetween, a second channel layerextending between the intermediate and bottom layers, the channel layerhaving a proximal end and a distal end and an elongate portion extendingtherebetween, an air leak disposed at the proximal end of the top layerconfigured to provide an air path into the first channel layer, andwherein one of the first and second channel layers comprises foam andthe other of the first and second channel layers comprising a fabric.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a negative-pressure system that can be used in thetreatment of wounds.

FIG. 2A illustrates an embodiment of a negative pressure wound treatmentsystem with a flexible shroud being applied over a flexible drape.

FIG. 2B illustrates the system of FIG. 2A with the shroud applied to theflexible drape.

FIGS. 2C-2F illustrates a method of applying the negative pressure woundtreatment system of FIGS. 2A and 2B to a patient.

FIG. 3A illustrates an embodiment of a negative pressure wound treatmentsystem with a sealing disc being applied over a flexible drape.

FIG. 3B is an exploded view of the sealing disc of FIG. 3A.

FIG. 3C illustrates the system of FIG. 3A with the sealing disc appliedto the flexible drape.

FIGS. 3D-3H illustrate a method of applying the negative pressure woundtreatment system of FIGS. 3A-3C to a patient.

FIG. 4A illustrates an embodiment of negative pressure wound treatmentsystem with a flexible drape having an integrated sealing ring.

FIG. 4B illustrates the system of FIG. 4A with a conduit insertedthrough the sealing ring.

FIG. 5A illustrates an embodiment of a negative pressure wound treatmentsystem using a suction adapter with an air leak.

FIG. 5B is an exploded view of the suction adapter of FIG. 5A.

FIGS. 5C-5F illustrate a method of applying the negative pressure woundtreatment system of FIGS. 5A-5B to a patient.

FIG. 6A illustrates an embodiment of a negative pressure wound treatmentsystem with a flexible suction adapter.

FIG. 6B is an exploded view of the flexible suction adapter of FIG. 6A.

FIGS. 6C and 6D are alternative embodiments of the flexible suctionadapter of FIGS. 6A-6B.

FIGS. 6E-6H illustrate a method of applying the negative pressure woundtreatment system of FIGS. 6A-6D to a patient.

FIGS. 7A-7B illustrate other embodiments of a flexible suction adapter.

FIG. 7C illustrates a negative pressure wound treatment system using aflexible suction adapter.

FIGS. 8A and 8B illustrate another embodiment of a negative pressurewound treatment system with a flexible suction adapter.

FIG. 9A illustrates an embodiment of a negative pressure wound treatmentsystem with a flexible drape integrating a suction channel therein.

FIG. 9B is an exploded view of the flexible drape of FIG. 9A.

FIG. 9C-9D illustrate a method of applying the negative pressure woundtreatment system of FIGS. 9A and 9B to a patient.

FIGS. 10A and 10B illustrate another embodiment of a negative pressurewound treatment system with a flexible drape integrating a suctionchannel therein.

FIGS. 11A and 11B illustrate another embodiment of a negative pressurewound treatment system with a flexible drape integrating a suctionchannel and spacers comprising bosses therein.

FIGS. 12A and 12B illustrate an embodiment of a flexible one-piecesuction adapter.

FIGS. 13A and 13B illustrate an embodiment of a negative pressure woundtreatment system with a drape-piercing suction adapter.

FIGS. 14A and 14B illustrate another embodiment of a negative pressurewound treatment system with an integrated drape and wound packingmaterial.

FIGS. 15A-D illustrate another embodiment of a negative pressure woundtreatment system with a flexible suction adapter.

FIGS. 16A-B illustrate another embodiment of a negative pressure woundtreatment system with a flexible drape integrating a suction channeltherein.

FIGS. 17A-B illustrate an embodiment of a negative pressure woundtreatment system with a low profile side drain.

FIGS. 18A-B illustrate an embodiment of a negative pressure woundtreatment system comprising a wicking layer.

FIGS. 19A-D illustrate embodiments of a negative pressure woundtreatment system incorporating a flat drain portion.

FIGS. 20A-B illustrate an embodiment of a negative pressure woundtreatment system incorporating a trimmable suction port.

FIGS. 21A-B illustrate another embodiment of a negative pressure woundtreatment system incorporating a sealing ring.

FIGS. 22A-B illustrate an embodiment of a negative pressure woundtreatment system incorporating a piercing attachment for use with aport.

FIGS. 23A-B illustrate a different embodiment of a negative pressurewound treatment system incorporating a piercing attachment for use witha port.

FIGS. 24A-B illustrate embodiments of a negative pressure woundtreatment system incorporating a piercing connector and a controlled airleak.

FIGS. 25A-B illustrate embodiments of a negative pressure woundtreatment system incorporating a manifold and a central controlled airleak.

FIGS. 26A-B illustrate embodiments of a negative pressure woundtreatment system incorporating two manifolds.

FIGS. 27A-C illustrate embodiments of a negative pressure woundtreatment system comprising a flexible suction adapter with separatecontrolled air leak paths.

FIGS. 28A-B illustrate an embodiment of a negative pressure woundtreatment system incorporating a controlled air leak in a suction head.

FIGS. 29A-B illustrate an embodiment of a negative pressure woundtreatment system incorporating a starburst negative pressuredistribution manifold and a central controlled air leak.

FIGS. 30A-B illustrate an embodiment of a negative pressure woundtreatment system provided with a piercing nozzle.

FIGS. 31A-B illustrate an embodiment of a negative pressure woundtreatment system with a port, a piercing connector, and a controlled airleak.

FIGS. 32A-K illustrate embodiments of a negative pressure woundtreatment system with a port and a piercing tool.

FIGS. 33A-H illustrate embodiments of a negative pressure woundtreatment system incorporating a cutting template.

FIGS. 34A-H illustrate embodiments of a negative pressure woundtreatment system comprising a soft port with a protruding channel.

FIGS. 35A-H illustrate an embodiment of a negative pressure woundtreatment with drape strips provided with a port.

FIGS. 36A-I illustrate a negative pressure wound treatment systemcomprising a drape with integrated drainage channels.

FIGS. 37A-G illustrate a negative pressure wound treatment systemincorporating a drape with miniature openings.

FIGS. 38A-I illustrate an embodiment of a negative pressure woundtreatment system comprising a bayonet connector between a ring and aport.

FIGS. 39A-B illustrate a negative pressure wound treatment systemcomprising a low-profile port configured to attach to a valve attachedto a drape.

FIG. 40 illustrates an embodiment of a negative pressure wound treatmentsystem provided with a low-profile fluidic connector.

FIGS. 41A-B illustrate an embodiment of a negative pressure woundtreatment system provided with a plurality of suction tubes.

FIGS. 42A-B illustrate an embodiment of a negative pressure woundtreatment system incorporating a pre-made aperture onto a drape.

FIGS. 43A-B illustrate an embodiment of a negative pressure woundtreatment system incorporating a piercing connector.

FIGS. 44A-B illustrate an embodiment of a negative pressure woundtreatment system with a drape incorporating an integrated suction port.

FIGS. 45A-C illustrate an embodiment of a negative pressure woundtreatment system incorporating a drape with cross-linked air channelsand port integrated thereupon.

FIGS. 46A-B illustrate an embodiment of a negative pressure woundtreatment system comprising suction channels integrated into a woundcover.

FIGS. 47A-B illustrate an embodiment of a negative pressure woundtreatment system incorporating a low-profile suction unit.

FIGS. 48A-E illustrate an embodiment of a negative pressure woundtreatment system comprising a flexible suction adapter sheet.

FIGS. 49A-B illustrate an embodiment of a negative pressure woundtreatment system incorporating a wound packing pouch.

FIGS. 50A-C illustrate embodiments of a negative pressure woundtreatment system comprising a port provided with a sealing ring.

FIGS. 51A-B illustrate another embodiment of a negative pressure woundtreatment system incorporating a low-profile suction adapter.

FIGS. 52A-B illustrate an embodiment of a negative pressure woundtreatment system provided with a bladder.

FIGS. 53A-D illustrate a different embodiment of a negative pressurewound treatment system provided with a bladder.

FIGS. 54A-B illustrate an embodiment of a negative pressure woundtreatment system using discrete wound packing material portions.

FIG. 55A illustrates an embodiment of a negative pressure woundtreatment system comprising a pump, and illustrating a flexible suctionadapter being applied to a wound.

FIG. 55B illustrates the embodiment of FIG. 55A, with the flexiblesuction adapter having been placed over a wound.

FIG. 55C illustrates an isometric view of a flexible suction adapterthat may be used in a negative pressure wound treatment system.

FIG. 55D illustrates an exploded view of the flexible suction adapter ofFIG. 55C.

FIG. 55E illustrates a close-up view of the proximal end of the flexiblesuction adapter of FIG. 55D.

FIG. 55F illustrates a close-up cutaway view of the proximal end of theflexible suction adapter of FIG. 55C.

FIG. 55G illustrates a top view of the flexible suction adapter of FIG.55C.

FIG. 55H illustrates a side view of the flexible suction adapter of FIG.55C.

FIG. 55I illustrates a bottom view of the flexible suction adapter ofFIG. 55C.

FIG. 55J illustrates an exploded view of an alternative flexible suctionadapter.

FIG. 56A illustrates a top view of a 3D fabric that may be used in anegative pressure wound treatment system.

FIG. 56B illustrates a bottom view of the 3D fabric of FIG. 56A.

FIG. 56C illustrates a side cutaway view of the 3D fabric of FIG. 56A.

FIGS. 57A-B illustrate an embodiment of a connector with two or moreprojections and that may be connected to a suction adapter illustratedin FIG. 55.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Preferred embodiments disclosed herein relate to wound therapy for ahuman or animal body. Therefore, any reference to a wound herein canrefer to a wound on a human or animal body, and any reference to a bodyherein can refer to a human or animal body. The term “wound” as usedherein, in addition to having its broad ordinary meaning, includes anybody part of a patient that may be treated using negative pressure.Wounds include, but are not limited to, open wounds, pressure sores,ulcers and burns. Treatment of such wounds can be performed usingnegative pressure wound therapy, wherein a reduced or negative pressurecan be applied to the wound to facilitate and promote healing of thewound. It will also be appreciated that the negative pressure systemsand methods as disclosed herein may be applied to other parts of thebody, and are not necessarily limited to treatment of wounds.

With reference initially to FIG. 1, treatment of a wound with negativepressure in certain embodiments of the application uses a system asillustrated schematically. In one embodiment, a wound 101 may be partlyor completely filled with a wound packing material 102, such as foam,gauze, or any other suitable material. Alternatively, no wound packingmaterial may be utilized. A flexible drape 103 that is at leastpartially fluid impermeable, and preferably liquid impermeable, may thenbe laid over the wound packing material 102 and preferably onto at leastpart of the surrounding healthy skin surrounding a wound. The drape 103may be connected via a conduit 104 such as a flexible tube to a sourceof negative pressure 106 such as a pump. This conduit 104 may, in someembodiments, comprise one or more tubes. Suitable sources for negativepressure include both powered negative pressure sources such as vacuumpumps, and manually powered negative pressure sources such as suctionbulbs. Negative pressure is applied to the wound through the conduit 104and through the wound packing material 102, and wound exudate and othersecretions are drawn away from the wound, through the wound packingmaterial, and into a canister or other collection unit 105. Thecollection unit 105 may be located along the conduit before the negativepressure source, or may be located elsewhere relative to the negativepressure source. In some embodiments, one or more filters 107 may beprovided along the vacuum pathway, for example at the outlet of thepump. This filter 107 may be useful for absorbing odors or may be abacterial filter. Suitable systems for treating wounds in the abovemanner include the RENASYS-F, RENASYS-G, RENASYS EZ and RENASYS GOsystems available from Smith & Nephew.

The application of reduced or negative pressure to a wound in the abovemanner may be used to promote faster healing, increase blood flow,decrease bacterial burden, increase the rate of granulation tissueformation, remove exudate and slough from the wound, alleviateinterstitial edema, stimulate the proliferation of fibroblasts,stimulate the proliferation of endothelial cells, close chronic openwounds, inhibit burn penetration, and enhance flap and graft attachment,among other things. It has also been reported that wounds that haveexhibited positive response to treatment by the application of negativepressure include infected open wounds, decubitus ulcers, dehiscedincisions, partial thickness burns, and various lesions to which flapsor grafts have been attached.

Suitable drapes such as those used in the embodiments described hereinare preferably liquid tight, such that at least partial negativepressure may be maintained at the wound site. The drape may beconstructed from, for example, transparent flexible plastics such aspolyurethane. Other suitable materials include without limitationsynthetic polymeric materials that do not absorb aqueous fluids,including polyolefins, such as polyethylene and polypropylene,polysiloxanes, polyamides, polyesters, and other copolymers and mixturesthereof. The materials used in the drape may be hydrophobic orhydrophilic. Examples of suitable materials include Transeal® availablefrom DeRoyal and OpSite® available from Smith & Nephew. In order to aidpatient comfort and avoid skin maceration, the drapes in certainembodiments are at least partly breathable, such that water vapor isable to pass through without remaining trapped under the dressing.Lastly, although several embodiments illustrated herein illustrate anoperator cutting an aperture into a drape manually, drapes used in theembodiments disclosed here may also be provided with one or more pre-cutapertures.

The wound is optionally filled with a wound packing material.Preferably, this wound packing material is conformable to the wound bed.This material is preferably soft and resiliently flexible. Examples ofsuitable forms of such wound fillers are foams formed of a suitablematerial, e.g. a resilient thermoplastic. Preferred materials for thepresent wound dressing include reticulated polyurethane foams with smallapertures or pores and open-celled foams. Other suitable materials mayinclude gauze. Preferably, such wound packing material will be able tochannel wound exudate and other fluids through itself when negativepressure is applied to the wound. Some wound packing materials mayinclude preformed channels or openings for such purposes.

Typically, the negative pressure wound treatment system is operateduntil a wound has reached a level of healing acceptable to a physician.The treatment system is preferably operated using a negative or reducedpressure ranging from about 40 to 200 mm Hg, though the amount may belower or higher depending on physician preference. The time period foruse of the wound treatment apparatus on a wound is selected by thephysician. During the time period that negative pressure is applied,dressing changes and other temporary interruptions to the treatment mayoccur. Preferably, the negative pressure wound treatment system is ableto handle at least 1 L of wound exudate or other fluid per day, or 0.694ml/min. Some embodiments may handle over 10 L of wound exudate per day.

In preparing a wound site for treatment with the embodiments describedherein, the wound is typically cleaned, debrided, and dried in amedically-acceptable manner. Optionally, the wound site may be filledpartly or completely with a wound packing material 102 as shown in FIG.1, including for example but without limitation gauze or foam. Thiswound packing material may be trimmed to fit into the wound space. Next,a drape 103 is placed to cover the wound site while overlapping onto thehealthy skin surrounding the wound; in some cases, the drape may need tobe trimmed to size. Depending on the type of drape, a skin sealant mayneed to be applied to the skin surrounding the wound prior to placingthe drape so that the drape may be adhered to the skin. Preferably, thedrape 103 has an adhesive layer on its wound-facing side. Once adheredto the skin, the drape should form an air-tight seal against the skin.In order to treat the wound using negative pressure, some embodimentsdisclosed herein may require that the drape be pierced (for example toinsert a conduit or to communicate with a suction adapter as describedbelow) to create an aperture leading to the wound site. Obviously, somedrapes may have an aperture or apertures already pre-cut or preformedinto the drape, and some embodiments disclosed herein may not require anaperture to be made (as shown in FIG. 1). After application of negativepressure to the wound site, wound exudate and other fluids may be drawnaway from the wound site and into a suitable receptacle 105, preferablyinterposed between the wound site and the source of negative pressure106. Application of negative pressure is continued (with interveningdressing changes, if necessary) until the wound has reached a desiredlevel of healing.

With reference to FIGS. 2A and 2B, one embodiment of a negative pressurewound treatment system 201 uses a flexible shroud 202 at the interfacebetween a flexible drape 203 and a conduit 204. In dressing a wound tobe treated using negative pressure, a wound packing material 205 asdescribed above may be appropriately sized and placed into the woundcavity. As shown in FIG. 2A, the wound packing material 205 may be afoam having an elongate groove or channel 207 for receiving conduit 204.The drape 203 may be placed over the wound and over the wound packingmaterial 205, with one or more apertures 206 formed through the drapethat permit wound exudate to be evacuated from the wound through tube204 leading to a negative pressure source. In order to effectivelyevacuate wound exudate from the wound, these drape apertures arepreferably made fluid-tight. In the illustrated embodiment of FIGS. 2Aand 2B, the flexible shroud 202 is placed over the aperture in the drapeand around the tube 204, permitting a fluid-tight connection to be madewithout the use of cumbersome tape, paste, or other such sealingmaterials typically used.

As shown in FIG. 2A, the flexible shroud 202 has a distal end 210 facingtoward the wound, and a proximal end 211 facing away from the wound. Thedistal end is enlarged relative to the proximal end to surround theaperture 206, giving the shroud in one embodiment the shape of a skirt.The distal end 210 preferably has a flat, distally facing surface, witha layer of adhesive 212 and a release layer 213 disposed on the distalend of the flexible shroud. The adhesive may be chosen from any adhesiveable to create a fluid-tight seal, including pressure-sensitiveadhesives such as silicone adhesives. In some embodiments, an adhesivelayer is not necessary, and the flexible shroud 202 is self-sealingagainst the drape, for example when suction is applied. In order to sealthe flexible shroud 202 against the conduit 204, a flexible grommet 214may be provided at the proximal end 211, although some embodiments mayhave the flexible shroud be sealed or molded to the conduit 204 withoutthe use of a grommet. The flexible shroud 202 may be fixed to a singlelocation on the conduit 204, or it may slide freely along it. If theflexible shroud 202 is fixed to a single location on the conduit 204, itmay be adhered to the conduit with any suitable means, includingadhesives such as cyanoacrylates, light-activated adhesives, or welding.

In a preferred embodiment, the flexible shroud 202 is constructed from apliable plastic material such as polyurethane. Preferably, the materialchosen for the flexible shroud 202 is soft and at least partiallyconformable to the skin of a patient to avoid causing pressure ulcers orother complications due to prolonged pressure onto patient skin or thewound site.

One method for using the negative pressure treatment system of FIGS. 2Aand 2B is illustrated in FIGS. 2C-2F. An operator may first debride andclean a wound in a typical manner known to a medical professional ofordinary skill in the art. As shown in FIG. 2C, a wound packing material205, as previously described, may then be placed into the wound; in somecases, the wound packing material may extend above the level of the skinin the wound. As also illustrated in FIG. 2C, a drape 203 may be placedover the wound and the wound packing material 205, preferablyoverlapping onto the healthy skin adjacent the wound. Preferably, thedrape is adhered to the skin and/or wound packing material. An aperture206 is then made into the drape as shown in FIG. 2D, preferably inproximity to the wound packing material 205 and along the groove 207formed in the wound packing material 205. Although FIG. 2D demonstratesan aperture 206 being made into the drape 203 with a pair of scissors,an aperture may be made by any suitable means, and in some embodiments,the drape 203 may be provided with an aperture pre-cut into the drape.As shown in FIG. 2E, a conduit 204 as described above is insertedthrough the aperture 206 and into the groove 207. In some cases,trimming or cutting of the tube may be necessary.

To apply the flexible shroud 202, as illustrated in FIG. 2F, releasesheet 213 is removed to expose the adhesive layer 212 of the flexibleshroud, and the flexible shroud is then adhered over and around theaperture 206 in order to create a fluid-tight seal. In certainembodiments, the shroud 202 may slide freely over the conduit 204; insuch cases, the shroud 202 is slid down and adhered around the aperture206. In other embodiments where the shroud 202 is attached to and doesnot slide freely over the conduit 204, the conduit 204 may need to betrimmed as needed to fit into the wound space under the drape 203.Preferably, the conduit 204 is slid into a groove 207 in the woundpacking material 205. Subsequently, the conduit 204 may be connected toa negative pressure source. When activated, the negative pressure sourcewill collapse the flexible shroud 202 (as shown in FIG. 2B) and drawwound exudate and other fluids from the wound area.

Turning to FIGS. 3A-3C, another embodiment of a negative pressure woundtreatment system 301 uses a sealing disc 302 to seal the interfacebetween the drape 303 and a conduit 304 in a fashion similar to what isdescribed above. In this embodiment, the sealing disc 302 comprises anannular lower support disc 310 preferably constructed from an at leastpartly-flexible material, such as a polyurethane layer, with a holethrough its center. On the bottom side of the lower support disc 310, anadhesive layer 312 may be disposed with an optional protective releaselayer 313 covering the adhesive layer, where the protective releaselayer may be removed prior to use. This adhesive layer 312 may be usedto adhere the sealing disc 302 to the drape 303.

Preferably, the sealing disc 302 further comprises a seal 311 placedabove the lower support disc 310, where the seal is able to create afluid-tight seal between itself and a conduit 304. The seal 311 ispreferably constructed from a flexible, conformable material such assilicone and comprises a central hole 316 that is preferably smallerthan the central hole in the support disc. The exact size of the seal311, and its relation in size to the support disc is not important, aslong as the seal is able to create a fluid-tight seal between itself andthe conduit 304. Some embodiments may comprise a lower support disc 310with a central seal 311 integrated into the middle of sealing disc 310(instead of above it), to create a one-piece unit construction.

Preferably, the sealing disc 302 also comprises an upper support disc315 placed above the other components of the sealing disc, such that theseal 311 is sandwiched between the upper support disc 315 and lowersupport disc 310. The top disc may be constructed from the same materialas the support disc, or it may be of a different material. Preferably,the top disc, the seal, and the support disc are secured together toform a single sealing disc 302, for example using means such asadhesives or welding.

To use the suction disc 302 described above, and with reference to FIG.3D-3H, an operator will typically prepare the wound as describedpreviously. Once the wound is prepared and a drape 303 placed over thewound (FIG. 3D), the drape 303 is pierced (FIG. 3E) and the sealingdisc's adhesive protective layer 313 is removed (FIG. 3F) and placedover the resulting aperture 306 (FIG. 3G). Preferably, the sealing disc302 is placed with its central hole 316 aligned with an aperture 306made through the drape 303. Subsequently, as shown in FIG. 3H, theconduit 304, which may be cut to size, is inserted through the sealingdisc 302 and into the drape 303, and connected to a source of negativepressure. In some embodiments, a channel 307 may be formed in the woundpacking material 305, such that the conduit 304 may be slid into thischannel 307. If necessary, a strip of tape or other adhesive 318 may beused to secure the conduit 304 to the drape 303 to prevent the conduit304 from undesired movement. The wound is then treated until it hasreached a desired level of healing.

FIGS. 4A-4B illustrate another embodiment of a negative pressure woundtreatment system 401. As illustrated, a flexible drape 403 includes anintegrated sealing ring 402 surrounding a pre-made aperture 406 in theflexible drape. The integrated sealing ring 402 (which may be similar tothe embodiment discussed in FIGS. 3A-C) should be of a diameter largeenough to permit passage of a conduit 404, but small enough so that asubstantially fluid-tight seal is maintained once the conduit 404 isinserted therein. The sealing ring 402 is preferably constructed from acompliant material such a silicone or urethane. Here, rather than usingan adhesive layer to attach the sealing disc to the drape as shown inFIGS. 3A-C, the sealing ring 402 is pre-attached to the drape 403, forexample by molding the ring 402 onto the drape 403.

In use and after preparation of the wound as described previously, andwith reference to FIG. 4B, a drape 403 is trimmed, if necessary, andsealed over a wound site optionally filled with a wound packing material405. A conduit 404 is inserted through the aperture 406 of theintegrated sealing ring 402. The tube 404, which may be cut to size, isconnected to a source of negative pressure, and the wound is treateduntil it has reached a desired level of healing.

In FIGS. 5A and 5B, another embodiment of a negative pressure woundtreatment system 501 is shown with a suction adapter 502 comprising anintegrated air leak. The suction adapter 502 comprises upper and lowerlayers 511 and 510, which may be annular and/or disc shaped as shown,and formed of a flexible plastic material. As illustrated in FIG. 5B,the conduit 504 is preferably sandwiched between the upper and lowerlayers 511, 510 and forms a loop within the upper and lower layers 511,510. The conduit 504 includes a plurality of apertures 515 in the loopedportion, and the lower layer 510 is provided with an aperture orapertures 516 enabling it to serve as a conduit for removing woundexudate from the wound through the drape aperture or apertures 506 andinto the apertures 515 of the conduit 504 sandwiched in the suctionadapter 502. Preferably, a layer of adhesive 512 is placed on the lowerportion 510 to provide for securing of the suction adapter to the drape.A protective release layer 513 removable by an operator may also beplaced on the adhesive layer to protect it during handling.

In some embodiments, the conduit 504 may be secured to the upper and/orlower layers 511, 510 using, for example, a strip of adhesive, clip, orother fixative 517. In some embodiments, the fixative 517 may serve as atargeting or visual indicator to aid in the placement of the suctionadapter 502 over the aperture 506. Preferably, the upper and lowerlayers 511, 510 of the suction adapter are sealed together with theconduit 504 to form a substantially fluid-tight suction adapter 502. Thesealing may be accomplished through any appropriate means, such asadhesives or welding.

The conduit 504 has a proximal end 518 leading toward a source ofnegative pressure and a distal portion inserted into the suction adapterwith its distal end 519 extending past the loop to form a controlled airleak 520. This air leak 520 provides a constant source of air enteringinto the suction adapter 502 and may aid in the removal of woundexudate. Additionally, this air leak 520, due to the constant rate atwhich air enters the negative pressure system, may be used in a feedbackmechanism to the pump control circuitry and may be useful in detectingblockages occurring in the system, for example in the conduit 504.Preferably, a filter 521 is placed at the end of the air leak 520 toprevent outside contaminants, such as microorganisms, dust, or otherforeign matter from entering the wound area. In some embodiments, thefilter 521 may be designed so that a patient may use the system 501 in ashower or other similar environment without occluding the air leak 520.The filter may be hydrophobic and/or oleophobic. Preferably, the airleak 520 supports a flow rate of air of at least 0.08 L/min. Someembodiments may support an air leak of at least 0.16 L/min.

In use, and as illustrated in FIGS. 5C-5F, an operator would prepare awound site in an acceptable manner as previously described. As shown inFIG. 5C, an optional wound packing material 505 may then be placed intothe wound site, which would then be covered by a drape 503,appropriately sized and sealed. After piercing the drape 503 (FIG. 5D),the adhesive protective layer 513 is removed from the suction adapter502 (FIG. 5E), placed over the drape aperture 506 (FIG. 5F), andconnected to a source of negative pressure (not illustrated). The woundis then treated substantially as described previously. Note that in thisembodiment, because the conduit 504 does not need to be inserted throughthe drape 503, no groove or channel in the wound packing material 505(which was preferably included in certain other embodiments disclosedherein) is needed in using this suction adapter 502.

FIGS. 6A-6D show another embodiment of a negative pressure woundtreatment system 601. The system comprises a wound packing material 605and flexible drape 603 as described above. A flexible suction adapter602 is further provided for connecting an aperture 606 in the drape to aconduit 604. Here, the suction adapter 602 is preferably formed of arelatively compliant and pliable material to avoid causing patientdiscomfort and injury, which may include pressure sores or ulcerations.The suction adapter 602 is connected via connectors 614, 615 to a sourceof negative pressure via the conduit 604. The connectors 614, 615 may beconstructed from a semi-rigid material, including for example butwithout limitation plastics such as acrylonitrile butadiene styrene(ABS). In some embodiments, end caps (not illustrated) may be providedto seal off one or more of the connectors 614, 615 when they aredisconnected from each other, so as to prevent wound exudate fromleaking out of the system.

The flexible suction adapter 602 comprises an upper layer or sheet 611,a lower layer or sheet 610, and an elongate channel 608 extendingbetween the upper and lower sheets having a proximal end 616 and adistal end 617. As illustrated, the channel preferably enlarges towardits distal end, and may form an elongated teardrop shape so as to permitnegative pressure to be applied to a larger wound area at the distal end617 while maintaining a smaller size at the proximal end 616 forconnecting with the conduit 604. Additionally, the teardrop shape aidsthe suction adapter 602 in conforming to different wound sizes andshapes. The channel 608 as illustrated includes a spacer 609 extendingbetween the proximal and distal ends, and at least one aperture 618 isformed on the lower sheet near the distal end 617 that permits fluid tobe evacuated from a wound area (in a manner similar to what has beenpreviously described). In some embodiments, there may be multipleapertures 618 to permit efficient transfer of fluid from the wound. Forexample, there may be four smaller apertures instead of one largeraperture. The spacer 609 is preferably constructed from a compliantmaterial that is flexible and that also permits fluid to pass through itif the spacer is kinked or folded over. Preferably, the spacer 619 issandwiched between the upper and lower layers 611 and 610, for exampleusing adhesives or heat-sealing. In order to secure the suction adapter602 over an aperture 606 on a drape, lower layer 610 may be providedwith a layer of adhesive 612 disposed on its underside, and with anoptional protective release sheet 613.

Suitable materials for the spacer 609 include without limitation foams,including open-cell foams such as polyethylene or polyurethane foam,meshes, 3D knitted fabrics, non-woven materials, and fluid channels.Advantageously, such materials used in the spacer 609 not only permitgreater patient comfort, but may also provide greater kink resistance,such that the spacer 609 is still able to transfer fluid from the woundtoward the source of negative pressure while being kinked or bent. Insome embodiments, the fluid channels may simply comprise folds createdwhen the upper sheet is wider than the lower sheet, or vice versa, suchthat application of negative pressure causes the wider sheet to collapseand form folds or wrinkles suitable to channel fluids from the wound tothe source of negative pressure. An example of such an embodiment isillustrated in FIG. 8A described below, where a suction adapter may beconstructed from a flexible and non-rigid material such as a film.

In other embodiments, and as illustrated in FIG. 6C, fluid channels maycomprise one or more solid channels 619, and may not require the use ofthe spacer 609 described above. In some embodiments, these solidchannels are molded into either or both the upper and lower sheets;alternatively, these may be constructed separately and inserted in thespace between the upper and lower sheets. If possible, such channels areat least partly compliant and non-rigid, thereby avoiding patientdiscomfort and other complications. FIG. 6D illustrates anotherembodiment where the spacer 609 comprises a thin mesh 620.

FIGS. 6E-6H illustrate a method of using and applying the suctionadapter 602 described above. The wound is prepared in an acceptablemanner as described above, and a drape 603 is fitted and sealed over thewound site (which may contain an optional wound packing material 605)(FIG. 6E). An aperture 606 is then cut into the drape 603 (although somedrapes may be provided with an aperture 606 already pre-cut) (FIG. 6F).The release layer 613, if present, is removed to expose the adhesivelayer 612 on the underside of the suction adapter 602 (FIG. 6G). Thesuction adapter 602 is then placed such that the apertures 618 on itsunderside are substantially aligned with the aperture 606 on the drape603. The suction adapter 602 is then connected to a source of negativepressure, and the treatment is applied until the wound has reached anacceptable level of healing.

FIGS. 7A-7B illustrate embodiments of the wound treatment system 701with an air leak provided, where the conduit used in FIGS. 5A-H isreplaced with a compliant material, for example foam. The compliantmaterial aspect of these two embodiments will be described in furtherdetail below. FIG. 7A demonstrates a suction adapter 702 similar indesign to FIG. 5A, but which uses a compliant material. Here, thecompliant spacer channel 707, preferably constructed from a compliantmaterial such as foam able to transmit fluid through itself, isconnected at its proximal end 718 to a conduit 704, which is thenconnected directly or indirectly to a source of negative pressure. Atthe distal end 719 an air leak 720 is provided, optionally with a filter721. This air leak provides a constant source of air entering thesuction adapter 702, and (as described previously in FIGS. 5 A-B) may beuseful in detecting blockages in the system (for example the conduit704) and may aid in the removal of wound exudate. Preferably, the filter721 is constructed from a thin membrane, which may be hydrophobic oroleophobic. The filter 721 is preferably able to filter microorganismsand foreign particles from entering the wound site. In some embodiments,the filter 721 is able to be wetted, for example when a patient enters ashower. The filter 721 may be die-punched from a membrane stock andattached to the air leak 720 by any suitable means, such as welding oradhesives. This compliant spacer channel 707 is sandwiched between anupper layer 711 and a lower layer 710, with the lower layer 710preferably being provided with a layer of adhesive optionally coveredwith a release layer in a similar fashion to the embodiments illustratedin FIGS. 5A-B. The lower layer 710 has one or more apertures permittingit to be fluidically connected to an aperture on a drape used to cover awound (not illustrated). The apertures on the lower layer 710 are alsofluidically connected to the compliant spacer channel 707, such thatupon the application of negative pressure, wound exudate and other suchfluids may be evacuated from the wound site through the aperture in thedrape, through the aperture in the lower layer 710, and into thecompliant spacer channel 707. Preferably, the section of the compliantspacer channel 707 situated over the apertures in the lower layer 710 islarger to permit more effective removal of wound exudate from the woundsite, and may form an elongated teardrop shape.

Focusing on the air leak aspect of these embodiments, FIG. 7Billustrates an embodiment with a controlled air leak 720 on the suctionadapter 702 that is provided at the proximal end 718 of the compliantspacer channel 707, instead of being provided at the distal end asdescribed above. A filter 721 is optionally provided at the air leaksite. The proximal end 718 is joined to a conduit 704. In a proximal airleak design, the air leak may be disposed at a “T”-junction between theapertures near the distal end and the proximal end of the spacer channel707 connected to the negative pressure source. Of course, although FIG.7B illustrates a proximal air leak using a foam fluid transfer material,such an embodiment could also be realized using other materials, forinstance the conduit used in FIG. 5A.

FIG. 7C illustrates an embodiment joining a compliant suction adapter702 and short compliant spacer channel 707 connected to a dual lumentube 704 incorporating an air leak 720 at the proximal portion 718.Here, one lumen in the tube 704 is fluidically connected throughconnector 730 to a source of negative pressure 731 at its proximal end718, and the other lumen is open at the proximal end 718 to form an airleak 720. This open end may optionally include an air filter 721. At thedistal end of the dual lumen tube, both lumens are fluidically connectedto the compliant spacer channel 707 to permit the application ofnegative pressure to the wound site through the suction head 702, in amanner similar to the other embodiments discussed above. In someembodiments, a compliant spacer channel 707 may not be necessary, andthe dual lumen tube 704 may be directly connected to the suction head.

FIGS. 8A-B illustrate a suction adapter 802 of a similar design to theembodiments described in FIGS. 6A-H. Here, however, the suction adapter802 is not filled with any material, and instead comprises a flatportion comprising elongate parallel channels 810 integrated onto theunderside of suction adapter 802. These channels 810 may be moldedintegrally or attached separately onto the suction adapter 802. Thesuction adapter 802 preferably comprises one or more apertures 816 thatwould permit a fluidic connection to be made between an aperture 806made in a drape 803, such that wound exudate from a wound site can bedrawn through optional wound packing means 805, through the aperture806, and into the suction adapter 802 through its aperture 816. Thewound exudate is then drawn off through the conduit 804. An adhesivelayer 812 is preferably provided on the underside of the suction adapter802 to permit it to be secured to the drape 803, and preferably includesa release layer 813 that is removed prior to adhesion of the suctionadapter 802.

FIGS. 9A and 9B illustrate an embodiment of the wound treatment system901 using a drape 903 with a suction channel 902 integrated therein. Inthis embodiment, the drape 903 typically used to cover the wound and theoptional wound packing material 905 that may be disposed in the woundalso serves as a suction channel 902 to transfer fluids such as woundexudate away from the wound using a source of negative pressure,connected to the drape 903 through conduit 904. The drape 903 includesat least one aperture 916 suitable for the passage of wound exudate. Aspacer 907 is preferably placed over the apertures 916, the spacer 907being preferably composed of the same types of materials as the spacer609 used in FIG. 6A, such as foam. The drape 903 comprises a top layer911 and a bottom layer 910. In order to create a fluid-tight seal, thetop layer 911 is attached to the bottom layer 910, sandwiching thespacer 907 between it. This top layer 911 should cover at least thespacer 907, and may be dimensioned to be as large or larger than thebottom layer 910 situated below it. The bottom and the top layers 910,911 may be attached together using any suitable means, for exampleadhesives or welding.

An adhesive layer 912 with an optional release sheet 913 is preferablydisposed on the wound-facing side of the bottom layer 910, as well as onthe wound-facing side of the top sheet 911, if the top sheet is largerthan the drape. The adhesive layer 912 preferably covers the entirewound-facing side of the drape 903, and may in some embodimentsincorporate a multi-part release sheet 913 rather than a single releasesheet 913. In this case, the release sheet 913 may be removable inseveral parts, for example to permit only a portion of the adhesive tobe exposed for initial placement on the wound site, followed by removalof another portion of the release sheet 913 once the drape placement isfinalized. The components of the assembled drape 903, including thedrape itself, the spacer, and the top layer, may also comprise markingsor other indicators, including visual or tactile indicators, to aid anoperator in aligning, positioning, and deploying the drape.

In order to use the wound treatment system 901 described above andillustrated in FIGS. 9C-D, a medical professional would to prepare awound site and optionally place wound packing material 905 inside thewound substantially in the manner described previously. Advantageously,instead of having to then place a drape over the wound site and createan aperture into the drape, a medical professional using a drape 903with an integrated suction channel would only have to position the drapeover the wound site, trim the drape 903 (if necessary), remove anyadhesive release layer 913 (FIG. 9C), and seal the wound by attachingthe drape 903 over the wound site (FIG. 9D). The drape 903 would then beconnected to a conduit 904. This drape 903 would thus save time andavoid complications and difficulties in having to size and cut a hole ina drape that the prior art and some of the other embodiments presentlyemploy.

In some embodiments, illustrated in FIGS. 10A and 10B (which is similarto the embodiment illustrated in FIG. 9A), the wound treatment system1001 incorporates a drape without a separate spacer. Instead, thesuction channel 1002 may comprise one or more ridges or folds 1010present on the underside of the suction channel 1002, the ridges 1010serving to maintain patency of the negative pressure connection from thewound to the source of negative pressure. In some cases, the ridges 1010may be molded into either the top layer or the bottom layer of the drape1003. Preferably, such ridges 1010 are substantially compliant andpliable to avoid causing patient discomfort and other complications.

FIGS. 11A-B demonstrate a variation of the embodiment illustrated inFIG. 9A, where wound treatment system 1101 uses a drape 1103incorporating a spacer comprised of bosses 1107 serving to keep the toplayer 1111 and bottom layer 1110 of the drape 1103 separate in order toform a suction channel 1102 for removal of wound exudate from a woundsite at the aperture 1116. These bosses 1107 may be molded into the topor bottom layer of drape 1103, or else may be constructed separately andattached thereto. In some embodiments, the bosses 1107 are solid; inother embodiments they may be hollow. Preferably, the bosses 1107 are atleast partially compliant and flexible, and may be formed from anysuitable material, such as flexible plastics including polyurethane. Thebottom layer 1110 optionally includes an adhesive layer and releasesheet.

FIGS. 12A-B illustrate a wound treatment system 1201 comprising aflexible one-piece suction adapter. Here, the suction adapter 1202 maybe manufactured from a compliant, flexible material such as plastic,including for example silicone, and comprises a proximal portion 1218and a distal portion 1219, where the distal portion 1219 comprises acentral aperture 1216 for placement around a wound site. The edges ofthe suction adapter may be chamfered (for example at chamfer 1206) tohelp seal the suction adapter against the edges of the wound site, andalso minimize the risk of the suction adapter snagging or catching onother tubes, dressings, or other materials that may be in proximity tothe wound site. Suction channels 1210 are also provided that serve todraw fluid away from the wound site through a conduit 1204 and toward asource of negative pressure connected thereto. In some embodiments,illustrated in FIG. 12B, the suction channels 1210 are formed throughthe proximal portion 1219 of the suction head, and are thus connected toa source of negative pressure. In other embodiments, illustrated in FIG.12A, the suction channels 1210 may not be enclosed on all or part of theskin-facing portion. Optionally, a layer of adhesive 1212 is present onthe wound-facing side of the suction head, although some embodiments mayinstead be self-sealing, for example if the suction head is constructedentirely or in part from silicone.

In use, once a wound site is cleaned, prepared in accordance withtypical medical protocols, and optionally filled with a wound packingmaterial, a first drape is placed over the wound and an aperture madethereon. Next, the suction adapter 1202 is placed over the drapeaperture, with the central aperture 1216 being placed over the drapeaperture. Subsequently, a second drape is placed over the wound site andsuction adapter 1202. After connecting the suction adapter to a sourceof negative pressure through the conduit 1204, wound exudate is removedfrom the wound and the wound may then progress to a desired stage ofhealing.

FIGS. 13A and 13B illustrate another embodiment of a wound treatmentsystem 1301 using a piercing cap 1302. Here, the piercing cap 1302 isprovided with a bayonet or other piercing element 1310 suitable forperforating a drape 1303 placed over a wound site. On the wound-facingside of the drape is a suction base 1307 adapted to fit together withthe piercing cap 1302, typically with a drape 1303 in between. Thesuction base 1307 is provided with a central aperture 1311 to be placedover the wound site. In order to fit together, the piercing cap 1302 andsuction base 1307 are preferably each provided with portions that lockand fit together, for example locking tabs or screw-like engagementmechanisms 1308 and 1309. In certain preferred embodiments (illustratedin FIG. 13B), the piercing cap 1302 rotationally engages with thesuction base 1307, thereby minimizing the force applied to the wound.Some embodiments may also include a sealing gasket to prevent air leaksbetween the interface of the piercing cap 1302 and the suction base1307, although the drape 1303 may in some cases provide a sufficientseal.

In use, a wound site is prepared substantially in the manner that hasbeen described previously above, but with a suction base 1307 beingprovided under the drape 1303 at the site over which a fluidicconnection is to be made. After the drape 1303 has been sealed over thewound site (which may optionally include a wound packing material 1305),a piercing cap 1302 pierces the drape and attaches to the suction base1307, thereby creating a fluidic connection enabling wound exudate to beconveyed from the wound site to the source of negative pressure througha conduit 1304. The wound site may then be maintained as such until ithas reached a desired stage of healing.

FIGS. 14A-B illustrate an embodiment of a wound treatment system 1401comprising a drape 1403 provided with a wound-packing material 1405integrated thereon. In this embodiment, a drape 1403 substantially ofsame material used in the other embodiments described herein is providedwith a wound packing material 1405, for example foam, attached to thewound-facing side of the drape 1403. Preferably, the adhesive does notattach the entire portion of the wound packing material to thewound-facing side of the drape, thus permitting a medical professionalusing the drape to easily trim the wound packing material to size.Optionally, precut or preformed detachable sections 1406 of woundpacking material may be provided. The drape may be secured to thewound-facing material by a patch of adhesive 1412 disposed in the centerof the drape 1403. In some embodiments, a channel 1407 may be providedthrough the wound packing material 1405, preferably through the center,so as to facilitate the placement of a conduit 1404 into the woundtreatment system 1401. Optionally, the wound treatment system 1401 maybe provided with such a conduit 1404 pre-attached or adhered into thechannel 1407. Such an arrangement may be advantageous in providingoptimal application of negative pressure to the wound site through theconduit 1404. Optionally, a seal bridge 1408 may be provided at thejunction where the conduit 1404 exits the drape 1403, thereby sealingthe wound site and preventing air leaks that may affect the applicationof negative pressure to the wound site. Preferably, the drape 1403 isprovided with a further adhesive layer (not illustrated here)surrounding the adhesive patch 1412 and extending to the edges of thedrape 1403, which is preferably covered with a release sheet (notillustrated here). Such a configuration permits an operator toaccurately place the wound treatment system 1401 over a wound site andseal the drape 1403 against the skin surrounding the wound site byremoving the release sheet once the drape 1403 and wound packingmaterial 1405 have been positioned and sized appropriately. In someembodiments, additional adhesives, for example sealing tape, may beprovided to aid in sealing the drape 1403 to the skin of a patient.

In order to use the wound treatment system 1401 described above, a woundsite is cleaned and prepared in any suitable manner. Next, the woundpacking material 1405 attached to the drape 1403 is fitted into thewound site, by trimming the wound packing material and/or by removingprecut or preformed sections 1406 (if so provided) as necessary as wellas by trimming the drape 1403 if necessary. A conduit 1404 is theninserted into a channel 1407, and after trimming (if necessary) andsealing the drape 1403 against the skin of the patient, the conduit 1404is connected to a source of negative pressure and the wound is treateduntil it reaches a desired level of healing. In some embodiments, theconduit 1404 is provided pre-inserted into the channel 1407.

FIGS. 15A-D illustrate an embodiment of a negative pressure woundtreatment system 1501 comprising a flexible suction adapter. This systemmay be combined with other components as described elsewhere in thisapplication, for example the components illustrated in FIG. 7C, andparticularly the source of negative pressure 731, tubing and a connector730. Here, the system 1501 may comprise a bridge 1502 having a proximalend 1503 and a distal end 1505 and an applicator 1520 at the distal end1505 of the bridge 1502. In some embodiments, the bridge 1502 maycomprise an upper channel layer 1512 sandwiched between an upper layer1510 and an intermediate layer 1514, with a lower channel layer 1516sandwiched between the intermediate layer 1514 and a bottom layer 1518.Preferably, the layers 1510, 1514, and 1518 have elongate portionsextending between proximal and distal ends and may be comprised of amaterial that is fluid-impermeable, for example polymers such aspolyurethane. It will of course be appreciated that the layers 1510,1514, and 1516 may each be constructed from different materials,including semi-permeable materials. Similarly to the embodimentdescribed in FIG. 6 with regards to the spacer 609, the upper and lowerchannel layers 1512 and 1516 are preferably elongate layers extendingfrom the proximal end 1503 to the distal end 1505 and may eachpreferably comprise a porous material, including for example open-celledfoams such as polyethylene or polyurethane. In some embodiments, one ormore of the upper and lower channel layers 1512 and 1516 may becomprised of a wicking fabric, for example a knitted or woven spacerfabric (such as a knitted polyester 3D fabric, Baltex 7970®, or Gehring8790) or a nonwoven fabric. These materials selected are preferablysuited to channeling wound exudate away from the wound and fortransmitting negative pressure and/or vented air to the wound site, andmay also confer a degree of kinking or occlusion resistance to thechannel layers 1512 and 1516. In some embodiments, the wicking fabricmay have a three-dimensional structure, which in some cases may aid inwicking fluid or transmitting negative pressure. To prevent the channels1512 and/or 1516 from being displaced or twisted while encased in thesystem 1501—which may impair performance of the respective channelsunder negative pressure—it may in some embodiments be preferable toadhere or otherwise secure the channels 1512 and/or 1516 to one or moreof the layers 1510, 1514, and 1518. In certain embodiments, includingwicking fabrics, these materials remain open and capable ofcommunicating negative pressure to a wound area under the typicalpressures used in negative pressure therapy, for example between 80 to150 mmHg. In some embodiments, the wicking fabric may comprise severallayers of material stacked or layered over each other, which may in somecases be useful in preventing the channel 1516 from collapsing under theapplication of negative pressure. In other embodiments, the wickingfabric used in channel 1516 may be between 1.5 mm and 6 mm; morepreferably, the wicking fabric may be between 3 mm and 6 mm thick, andmay be comprised of either one or several individual layers of wickingfabric. In other embodiments, the channel 1512 may be between 1.2-3 mmthick, and preferably thicker than 1.5 mm. Additionally, and asdescribed previously, the materials used in the system 1501 arepreferably conformable and soft, which may help to avoid pressure ulcersand other complications which may result from a wound treatment systembeing pressed against the skin of a patient.

Preferably, the distal ends of the layers 1510, 1514, and 1518 and thechannels 1512 and 1516 are enlarged at the distal end (to be placed overa wound site), and may form a “teardrop” or other enlarged shape.Preferably, and with additional reference to FIG. 15C, a connector 1504is provided at the proximal end 1503 which may be used to connect thelower channel layer 1516 to a source of negative pressure. The connector1504 may for example be embedded into the lower channel layer 1516, andpreferably extends sufficiently away from the assembled bridge 1502 soas to permit a fluidic connector, for example a tube, to be connected toit so as to permit wound exudate to be suctioned away from the wound andfor negative pressure to be applied to the wound site. The upper layer1510 may comprise additional material extending downward, preferably atleast of the thickness of the bridge 1502. During assembly, the upperlayer 1510 is preferably attached, for example by melting, welding, orwith adhesives, to the lower layer 1518 so as to form a fluid-tight seal(with the exception of the apertures at the distal and proximal ends).Preferably, the middle layer 1514 is attached to the top layer 1510 andthe bottom layer 1518. Note that FIG. 15C is intended to illustrate thevarious materials and components at the proximal end 1503, and that asystem 1501 constructed accordingly will preferably not have theproximal end 1503 open and unsealed. In some embodiments, it will bepreferable to attach or bond the connector 1504 to at least one of thelayers 1510, 1514, 1518 so as to create a fluid-tight connection.

In certain embodiments, a controlled air leak 1524 may be disposed onthe bridge portion 1502, for example at the proximal end thereof. Thisair leak 1524 may comprise an opening or channel extending through upperlayer 1510, such that the air leak 1524 is in fluidic communication withthe upper channel 1512. Upon the application of suction to the system1501, air will enter through the air leak 1524 and move from theproximal end 1503 to the distal end 1505 along the upper channel 1512.The air will then be suctioned into the lower channel 1516 by passingthrough the apertures through the distal ends of the layers 1512, 1514,1516 and 1518. The air leak 1524 preferably comprises a filter (notillustrated), which may be similar in function to the filter 521illustrated in FIG. 5A. Preferably, the air leak 1524 is located at theproximal end of the bridge portion 1502 so as to minimize the likelihoodof wound exudate or other fluids coming into contact and possiblyoccluding or interfering with the air leak 1524 or its filter. In someembodiments, this filter is a microporous membrane capable of excludingmicroorganisms and bacteria, and which may be able to filter outparticles larger than 45 μm.

Advantageously, some embodiments may provide for a filter that is atleast partially chemically-resistant, for example to water, commonhousehold liquids such as shampoos, and other surfactants. In someembodiments, reapplication of vacuum to the system 1501 and/or wiping ofthe outside portion of the filter may be sufficient to clear any foreignsubstance occluding the filter. The filter may be composed of asuitably-resistant polymer such as acrylic, polyethersulfone, orpolytetrafluoroethylene, and may be oleophobic and/or hydrophobic. Insome embodiments, the filter may also comprise a supporting backinglayer, for example a nonwoven polyester support. Preferably, the airleak 1524 will supply a relatively constant air flow that does notappreciably increase as additional negative pressure is applied to thesystem 1501. In embodiments of the system 1501 where the air flowthrough the air leak 1524 increases as additional negative pressure isapplied, preferably this increased air flow will be minimized and notincrease in proportion to the negative pressure applied thereto.

The system 1501 is preferably constructed so as to provide a consistentfluid flow even if the system 1501 is kinked or weighted down. Forexample, in use on a patient, the bridge portion 1502 may become foldedover itself, or else the patient may roll over, thus placing his or herweight over at least a portion of the system 1501. Typically, prior artdressings and fluidic connectors become blocked or ineffective in suchsituations. Here, however, certain embodiments provide for improvedblockage resistance if kinked or weighed down. Preferably, the system1501 is able to maintain a flow rate through the air leak 1524 of atleast 0.08 L/min, and preferably 0.12 L/min while negative pressure isapplied through a source of negative pressure. Further embodiments alsoprovide for the system 1501 to be able to handle fluid exudate drainagefrom the wound site through the lower channel 1516 of at least 10 L/day,or 6.9 ml/min. Certain embodiments provide for the system 1501 tomaintain these flow rates with a weight, for example a 12 kg weightpressing down on the bridge portion through a rod with a 1 in. diameter.In some embodiments, these flow rates are also maintained while thebridge portion 1502 is kinked over itself with the same weight, or forexample with a 4.75 kg weight placed directly on the folded region. Itis preferable that the system 1501 be able to withstand being folded orkinked over even during an extended period of time, for example over 40hours. Preferably, embodiments of the system 1501 are also able totransmit and maintain a negative pressure at the wound that is close tothe negative pressure level at the source of negative pressure. Forexample, an acceptable level of pressure maintained at the wound may bewithin .+−0.25 mmHg of the negative pressure set at the source ofnegative pressure, with this pressure being preferably maintained atthis level within for example 95% of the time that the system 1501 hasnegative pressure applied to it. Acceptable pressure levels may includepressure ranges between 40-120 mmHg, although levels of 200 mmHg havesuccessfully been used.

With additional reference to FIG. 15D, the system 1501 also comprises anapplicator 1520 designed for placement over a wound site. Preferably,the applicator 1520 comprises a flexible layer 1530, for examplepolyethylene or polyurethane, with a layer of adhesive on its lower(wound-facing) side. Optionally, a protective release layer 1532 may beplaced on the adhesive layer, which is removable before use. In someembodiments, a more rigid removable backing layer 1534 may be providedto facilitate handling of the applicator 1520 due to its flexibleadhesive-backed layer 1530. The applicator 1520 preferably comprises anattachment point for the bridge 1502 at the distal end 1505, for exampleusing a section of double-sided adhesive tape 1528. The double-sidedadhesive tape 1528 may be protected by an additional protective releaselayer 1529, which is removed prior to adhering the bridge 1502 to theapplicator 1520. It will be understood that different attachment methodsare also contemplated, for example heat sealing, welding, or suitableadhesives. Some embodiments may also permit the manufacture of thebridge 1502 and the applicator 1520 as a single unit that does notrequire separate attachment means. The applicator 1520 preferablycomprises at least one aperture 1526 through itself and designed to beplaced over a wound site, and which can serve to fluidically connect thewound site to the source of negative pressure and to the air leak whilealso serving as a conduit to draw out wound exudate from the wound site.Additionally, certain embodiments may provide for the aperture 1526 tobe used in a viewing window 1522 described below.

With continued reference to FIGS. 15A-B, certain embodiments may alsoprovide for a viewing window 1522 that permits targeting andvisualization of the wound site prior to placement of the system 1501 aswell as ongoing monitoring of the wound site during the course oftreatment. Preferably, a set of apertures are created or formed throughthe distal portions of layers 1510, 1512, 1514, 1516, and 1518 inalignment with aperture 1526 through the applicator 1520. Although FIG.15B illustrates a set of apertures with a circular cross-section, othercross-sections are possible, for example with a polygonal or rectangularcross-section. Preferably, a viewing window 1522 which is at leastpartially transparent is provided to cover the first aperture throughthe top layer 1510 to shield the wound from contamination.

The filter provided in the controlled air leak 1524 in certainembodiments may be useful in a system 1501 for use with more ambulatoryand active patients. For example, a chemically-resistant filter maypermit a patient to bathe or shower without damaging the filter'sfunctionality when reconnected to a source of negative pressure. Anyocclusion or fluid blocking the air leak 1524 could then be cleared by,for example, wiping off the filter or re-applying negative pressure tothe system 1501. Such a system would also have the advantage that thesystem 1501 and any assorted wound dressing materials, if present, wouldnot need to be removed and then re-applied should a patient need to bedisconnected from the source of negative pressure, for exampleincidental to bathing. This would entail significant advantages inimproving the cost-effectiveness and ease of use of the presenttreatment system.

In use, the system 1501 may be used in a similar fashion to the otherembodiments previously disclosed herein. A wound site is preferablycleaned and prepared in a suitable fashion, and a wound packingmaterial, if necessary, placed into the wound site, followed by a drape.An opening through the drape to the wound site is then created, althoughsome embodiments may have a pre-made aperture. Subsequently, an operatormay situate the applicator portion 1520 over the aperture, optionallyusing the viewing window 1522 as a positioning aid. After removing thebacking layer (if present) from the adhesive layer on the underside ofthe applicator portion 1520, the applicator is sealed to the drape, andthe support layer (if present) is also removed from the applicatorportion 1520. A fluidic conduit such as a tube may then be connected tothe connector 1504. After the fluidic conduit is connected to a sourceof negative pressure, preferably with a container suitable forcontaining wound exudate interposed therebetween, the application ofnegative pressure may then be effectuated to the wound site until thewound site progresses to a desired level of healing.

During use of the system 1501, wound exudate is drawn by the negativepressure through the lower channel layer 1516. The air leak 1524 allowsair to pass through the upper channel layer 1512 into the aperturesthrough the distal ends of the layers 1512, 1514, 1516 and 1518. Thenegative pressure draws air passing through the upper channel layer intothe lower channel layer 1516 back toward the source of negative pressureor pump. In some embodiments, the controlled air leak 1524 provides aconstant flow of air through the system 1501, which then may be used todetermine whether blockage or leakage is present. Causes of blockage caninclude, for example, situations where the lower channel 1516 becomesoccluded with wound debris. Leakage causes can include, for example,improper sealing of the drape over the wound site, or physical damage tothe system 1501 leading to excess air leaking into the system. Theblockage or leakage may be determined, in certain embodiments, bymeasuring the speed of the pump while the pump works to maintain aconstant negative pressure. Pump speed may also be measured indirectlyby measuring the amount of voltage or signal sent to the pump.

FIG. 16A illustrates a wound treatment system 1601 similar to theembodiment described in FIG. 9. Here, a top layer 1603 (illustrated witha square or rectangular shape) is preferably constructed from aliquid-impermeable material, although it is preferably at leastpartially gas and water vapor permeable. A bottom layer 1607(illustrated with a square or rectangular shape) may then be attached orbonded to the top layer 1603, for example using adhesives or welding,while sandwiching a wicking layer 1605 between these two layers. Thebottom layer preferably has a layer of adhesive (not illustrated)disposed on at least part of the wound-facing side, which may beprotected by an optional protective layer 1608 (illustrated in FIG.16B). Preferably, at least the layers 1603, 1607, and 1608 areconstructed of a material that is easily cut, for example with scissors,so that the system 1601 may be sized as appropriate for placement over awound site.

The bottom layer 1607 preferably has at least one aperture 1606 capableof creating a fluidic connection between a wound site disposed under theaperture and the wicking layer 1605. This wicking layer 1605 ispreferably an elongate layer placed between the layers 1603 and 1607,constructed from a material capable of wicking or transporting fluidfrom a wound site, especially while under suction. Suitable materialsinclude but are not limited to foams as described above, wovenmaterials, 3D knitted materials, materials constructed of from either orboth hydrophilic materials (such as cotton), hydrophobic materials (suchas polyethylene), or a mixtures of both. Either or both the top orbottom layers may have a channel 1612 suitable for containing thewicking layer 1605, and this channel and wicking layer are preferablyenlarged at the distal end closest to the aperture 1606. As illustrated,the wicking layer 1605 has an enlarged end with a circular shape placeover the aperture 1606. Preferably, a fluidic connector 1610 is attachedto the top layer 1603 to permit a suction tube or other conduit 1604 tocreate a fluidic connection between the wound space, the wound treatmentsystem 1601, and a source of negative pressure.

FIG. 16B illustrates a method of using the system 1601, where the system1601 is cut to size and secured to the wound. In some embodiments, astrip of tape or other fixative may be used to secure the tube 1604 tothe connector 1610.

FIG. 17A illustrates an embodiment of a negative pressure woundtreatment system 1701. The system 1701 preferably has a low-profile port1712 integrated into a drape 1703 (illustrated with a square orrectangular shape), where the port 1712 preferably situated along oneside of the drape 1703. The port 1712 is preferably sized to permit oneside of a fluidic connector 1710 to be connected to it. The other sideof the connector 1710 is preferably sized to permit a conduit or tube1704 to be connected, although some embodiments may permit the conduit1704 to be connected directly to the port 1712 without the use of aconnector 1710. Preferably, the port 1712 is attached over an aperturethrough the drape 1703, permitting a fluidic connection to be made fromthe wound site through the port 1712, through the fluidic connector1710, and into the conduit 1704, which is preferably connected to asource of negative pressure. A layer of adhesive may also be provided onall or some of the wound facing side of the drape 1703, and which may beprotected by a release layer 1708.

FIG. 17B illustrates a method of using the system 1701 described above,where the drape 1703 is cut to size and applied to the wound.

FIG. 18A illustrates an embodiment of a negative pressure treatmentsystem 1801 similar to FIG. 6A. In a preferred embodiment, a flexiblewicking layer 1805 is sandwiched between a top layer 1803 and a bottomlayer 1808, where the bottom layer 1808 is preferably provided with atleast one aperture 1806 to expose the wicking layer to a wound site.Similarly to other embodiments, an adhesive layer and an optionalprotective layer may be disposed on the wound-facing side of the bottomlayer 1808. A fluidic connector 1810 may be disposed at the proximal endof the system 1801 so as to create a fluidic connection between thewound site and a source of negative pressure through a conduit 1804.Preferably, the system 1801, and in particular the layers 1803, 1805,and 1808, are flexible and conformable to aid in the placement over awound site located on, for example, a non-flat or difficult to accessarea of the body, such as a heel.

FIG. 18B illustrates a method of using the system 1801. As illustratedthe system 1801 is applied to a drape having an incision or holeextending through the drape. In some embodiments, a strip of tape orother fixative may be used to secure the tube 1804 to the connector1810.

FIGS. 19A-B illustrate embodiments of a negative pressure treatmentsystem 1901. With reference to FIG. 19A, the system 1901 comprises anexposed wicking layer 1905 extending from a flat drain portion 1903. Thedrain portion 1903 is preferably integrated with a tube or conduit 1904,and tapers down to become wider and flatter at its distal end.Preferably, the drain portion 1903 and the conduit 1904 are formedtogether as a single unit. The drain portion 1903 is also preferablyconstructed from a soft elastomeric material, including for examplesilicone, polyurethane, polyethylene, and/or polyvinylchloride, andwhich is able to conform to a wound site and spread out any pressureover a larger area. The wicking portion 1905 is preferably constructedfrom a soft material able to transmit fluid along itself, for example anonwoven, open textile material (such as cotton gauze or XD spacerfabric (Baltex®)), thereby permitting it to be placed over or into awound site so as to drain wound exudate and transmit negative pressureto the wound site. Some embodiments of the system 1901 may also providefor a controlled air leak 1916, similar to the air leak 1524 describedin FIG. 15A. In certain embodiments, this air leak 1916 may be in theform of a one-way valve which opens and permits air to enter the systemwhen high negative pressure is applied.

FIG. 19B illustrates another embodiment of the negative pressuretreatment system 1901. Here, the drain portion 1903 may be partlybifurcated to permit a lumen 1918 attached to a controlled air leak 1916to reach the area close to the wound site. This air leak 1916 preferablyincludes a filter element 1917 to prevent particulates and othercontaminants from entering the wound site. The drain 1903 is preferablyflat and tapered so as to present a low profile on the wound, and ispreferably constructed of a soft elastomeric material of the typedescribed above. To facilitate drainage of exudate from the wound, anaperture or apertures 1906 may be provided along the wound-facingportion of the drain. Turning back to the air leak 1916, certainembodiments provide for the proximal end of the air leak 1916 (closestto the air filter 1917) to be accommodated on a suction adapter 1910,for example in a notch 1920 made in the adapter 1910. The suctionadapter 1910 is preferably designed to receive a tube or conduit 1904and connect it to the drain 1903.

FIGS. 19C-D illustrate methods of using embodiments of the system 1901described above.

FIG. 20A illustrates an embodiment of a negative pressure woundtreatment 2001 comprising a trimmable suction port. A suction head 2006is attached to a tail 2008 (although the head 2006 and tail 2008 may beformed as a single unit), where the tail 2008 comprises a channel 2009disposed longitudinally inside to create a channel leading from thewound site, through at least one aperture 2012 disposed on thewound-facing side of the suction head 2006, and to a source of negativepressure. Preferably, this channel 2009 is sized to accommodate theinsertion or attachment of a suction adapter 2010 and/or a conduit ortube 2004. The head 2006, although illustrated as being round, may be ofany suitable shape, and preferably comprises a layer of adhesivedisposed on its wound-facing side for attachment to a drape. Similar topreviously-described embodiments, this adhesive layer is preferablyprotected by a removable backing layer.

The suction adapter 2010 may be sized to taper from a shorter, widercross-section at its distal end inserted into the channel 2009 to arounder profile at its proximal end to permit insertion or attachment ofa tube 2004. Some embodiments may provide for a controlled air leak 2016similar in design to other examples previously illustrated.

The tail 2008 is preferably constructed from a flexible, conformablematerial capable of being trimmed or cut, for example during sizing ofthe system 2001 for placement over a wound site. Accordingly, anoperator may trim the tail 2008 as appropriate for the size and locationof the wound site, followed by the insertion of, preferably, the suctionadapter 2010 into the channel 2009, although some embodiments providefor the insertion of a tube 2004 directly into the channel 2009 withoutnecessitating the use of a suction adapter 2010.

FIG. 20B illustrates a method of using the system 2001 described above.

FIG. 21A illustrates another embodiment of a negative pressure woundtreatment system 2101 comprising a sealing ring similar to the system301 illustrated in FIG. 3A. Here, a sealing disc 2103 is preferablyconstructed from a flexible, resilient material able to seal against atube or conduit 2104 that is inserted through the sealing disc 2103'scentral aperture 2106 so as to create a fluid-tight seal. A preferredmaterial may include silicone or polyurethane, although hydrogels may beused as well. Preferably, an adhesive layer 2108 is disposed on thewound-facing side of the disc 2103, optionally protected by a removablebacking layer.

In use, and with further reference to FIG. 21B, the sealing disc 2103 ispositioned over a drape covering a wound site, and the adhesive layer ofthe disc adhered to the drape. Flaps 2110 may also be provided to form atemplate or cutting guide for cutting a hole through the drape, inaddition to serving as additional sealing means against the tube 2104.In some embodiments, the flaps 2110 may be arranged, for example, toform a cross or “X” shape, such that a cutting implement such as ascalpel can be used to form a correspondingly-sized aperture in theunderlying drape. Subsequently, a conduit 2104 may be pushed through theaperture created through the drape. After verifying that the conduit2104 has formed a fluid-tight seal against the disc 2103 and/or theflaps 2110, negative pressure therapy may be applied until the wound hasreached a desired stage of healing.

FIG. 22A illustrates an embodiment of a negative pressure woundtreatment system 2201 incorporating a suction port with a piercingattachment. The system 2201 comprises a port 2203 adapted for placementover a wound site, and more preferably over a drape situated over awound site prepared substantially in the same manner as previouslydescribed. The port 2203 preferably comprises an aperture 2218 forplacement over a wound site, and this side of the port 2203 preferablycomprises an adhesive layer 2216, optionally protected with a backinglayer and adapted to adhere to a drape or to patient skin. The port 2203preferably also comprises a side aperture 2206 sized to permit a fluidicconnector 2210 to be connected to it. Advantageously, some embodimentspermit for the port 2203 to be of a relatively small size, such thatsmaller wounds may be effectively treated. In some embodiments, theconnector 2210 may comprise a piercing end 2212, where this piercing tip2212 is sharpened or otherwise adapted to perforate a drape positionedover a wound site when pushed through the aperture 2206 so that the tip2212 extends past the lower aperture 2218. This tip 2212 may also beadapted to create a fluidic connection between a tube or conduit 2204connected to it. The other side of the fluidic connector 2210 ispreferably a blunter and shorter end 2214. This end 2214 is preferablyable to create a fluid-tight seal between the fluidic connector 2210 andthe aperture 2206, and preferably does not extend past the aperture 2218when inserted into the aperture 2206. Preferably, the port 2203 alsocomprises a controlled air leak 2216 similar to the embodimentspreviously described, and which may be provided with a filter 2217.

In use, and with further reference to FIG. 22B, a wound site may beprepared substantially in a manner previously described and sealed witha drape. The port 2203 may then be situated over an appropriate positionover the drape, and then adhered to the drape. The piercing tip 2212 ofthe fluidic connector 2210 may then be pushed through the side aperture2206 and past the bottom aperture 2218 so as to create an aperture inthe drape positioned over the wound site. The connector 2210 may then bepulled out from the wound site and reversed so that the blunt end 2214may then create a fluid-tight seal to the aperture 2206. The piercingtip 2212 may then be connected to a tube 2204, for example by slippingthe end of the tube 2204 over the end 2212, although other connectionmeans are possible. A suction source may then be activated, and negativepressure is applied to the wound and wound exudates and other materialssuctioned from the wound site until the wound has reached a desiredlevel of healing.

FIG. 23A illustrates a fluidic connector used in a negative pressurewound treatment system 2301. This system 2301 preferably comprises aport 2303, which may be shaped in a low-profile bridge shape with a flatside against a wound site. The port 2303 is preferably placed under adrape, with the drape sealed over it. Preferably, the port 2303comprises at least one aperture 2306 on its wound-facing side, adaptedto convey fluid away from a wound site and negative pressure to a woundsite. The port 2303 may also be provided with a side aperture 2308leading into a channel 2309, where the channel 2309 connects to theaperture 2306. The aperture 2308 and channel 2309 are preferably sizedto receive a piercing fluidic connector 2310. This connector 2310 may beprovided with a piercing tip 2312 at its distal end, where the piercingtip 2312 is sharpened or otherwise designed to create an aperturethrough a drape placed over the port 2303 to permit a fluidic connectionto be made between the connector 2310 and the port 2303. Preferably, theport 2303 is constructed from a softer, more conformable material whichmay also serve to seal against the connector 2310 to aid in creating afluid-tight seal. Some embodiments may provide for the connector 2310 tohave a controlled air leak 2316, which may also be provided with afilter or a one-way valve. The one-way valve may be designed to openonly under high negative pressure. The connector 2310 preferablycomprises an aperture on its underside (not illustrated) so as to createa fluidic connection between itself and the aperture 2306. The proximalside 2314 of the fluidic connector is preferably constructed so as to beable to attach or connect a tube or conduit 2304 to it, where the tube2304 is connected to a source of negative pressure.

FIG. 23B illustrates a method of using the system 2301 described above.

FIGS. 24A-B illustrate an embodiment of a negative pressure woundtreatment system 2401 which comprises a port 2405 situated under a drape2403 pierceable by a piercing fluidic connector 2410. The port 2405 ispreferably situated over a wound site in need of treatment, and sealedunder a drape 2403, although certain embodiments may instead provide forthis port 2405 to be provided with adhesive means enabling it to besituated over an aperture made in a drape 2403. The port 2405 preferablycontains at least one large aperture 2406 on its wound-facing sidepermitting the application of negative pressure to the wound and theremoval of exudate from the wound site, in addition to two side ports2420, 2422. The system 2401 preferably comprises a piercing fluidicconnector 2410 provided with piercing tips 2412, 2413 able to piercethrough the drape 2403 so as to fluidically connect to apertures 2420,2422. One tip, illustrated for example here as tip 2412, may be used tocreate a fluidic connection from a tube or conduit 2404 through to theaperture 2420, where the tube 2404 is connected to the fluidic connector2410 through hose fitting 2418. Another tip, illustrated for example astip 2413, may serve as to create a conduit suitable for a controlled airleak 2415 through the aperture 2422 similar to those previouslydescribed. An air filter 2416 may optionally be provided.

FIGS. 25A-B illustrate an embodiment of a wound treatment system 2501comprising a drape 2503 with a manifold 2520 integrated therein. Incertain embodiments of the system 2501, a drape 2503 is provided whichis trimmable and may be sealed over a wound site. A manifold 2520 mayintegrated or attached over a portion of the drape 2503 preferably thesection of the drape 2503 which is to be placed over a wound site to betreated—and the manifold 2520 may contain multiple apertures orperforations suitable for channeling suction to the wound site and forsuctioning away exudate and other fluids from the wound site.Preferably, a controlled air leak 2514 is provided that is in fluidcommunication with the wound site, and may for example be located in themiddle of a loop that may be formed with the manifold 2520 around awound site. This air leak preferably comprises a filter 2515. Themanifold 2520 is preferably connected to a fluidic connector 2510, whichmay be used to connect to a tube or conduit 2504.

FIGS. 26A-B illustrate an embodiment of a negative pressure woundtreatment system 2601 of a similar construction to the embodimentsillustrated in FIGS. 25 A-B, but with an air leak 2614 provided on afluidic connector 2610 rather than being formed in a central aperture. Amanifold 2620 is preferably integrated or attached to the drape 2603,preferably in a semi-circular or looped configuration, with perforationsor apertures suitable for conveying negative pressure and/or exudatefrom the wound site. This manifold 2620 is preferably connected to thefluidic connector 2610 so as to fluidically connect the wound site witha tube or conduit 2604 connected to a source of negative pressure. Asecond manifold 2621, connected to the air leak 2614, is preferablyarranged in a similar semi-circular or looped arrangement around themanifold 2620, and permits air from the outside environment to enterinto the wound site. Preferably, the air leak 2614 is protected with afilter 2615 to prevent outside contaminants from entering the woundsite. In a similar fashion to the embodiment described in FIGS. 25 A-B,the drape 2603 may be trimmable for sizing purposes and may be sealedover a wound site.

FIGS. 27A-C illustrate an embodiment of a negative pressure woundtreatment system 2701 comprising a conformable wound drainage devicewith separate controlled air leak paths. In a preferred embodiment, adrape 2703 is provided with a conformable suction bridge 2712 preferablyconstructed from a fluid-impermeable material 2722. The bridge 22712 ispreferably filled with a fluid-channeling material 2720, for exampleopen-celled foam, that is at least partly resistant to occlusion due topressure or kinking. The bridge 2712 may be bonded to or integrated withthe drape 2703, or may be attached using any suitable means. The bridge2712 is preferably provided with one or more apertures on itswound-facing side to permit wound exudate to be drawn away from thewound site using a source of negative pressure. The source of negativepressure is connected to the system 2701 through a conduit 2704 attachedto a fluidic connector 2710 connected to the bridge 2712. A controlledair leak 2714 may also be provided at a location separate from thebridge 2712, with one or more air channels 2716 connecting to one ormore apertures 2718 located near the wound site. Preferably, the airleak 2714 is provided with a filter 2715.

FIGS. 28A-B illustrate embodiments of a negative pressure woundtreatment system 2801 comprising a controlled air leak 2814 integratedinto a portion of a suction head 2805. The air leak 2814 causes air tobe drawn into the suction head 2805, aiding in suctioning exudate fromthe wound site through the aperture or apertures 2806 disposed on thewound-facing side of the suction head 2805. Similarly to otherembodiments, a fluidic connector 2810 provides a connection between atube or conduit 2804 leading to a source of negative pressure and thesuction head 2805. Preferably, the suction head 2805 has a layer ofadhesive on its wound-facing side to permit attachment over an aperturemade on a drape 2803 situated over a wound site. Other embodiments mayinstead provide for the drape 2803 to be integrated or attached to thesuction head 2805 with a pre-formed aperture to be situated over thewound site.

FIGS. 29A-B illustrate embodiments of a negative pressure woundtreatment system 2901 comprising a distributed negative pressuremanifold. The system 2901 comprises a suction tail 2905 connected orattached to a suction head 2908, where the head 2908 comprises one ormore projections 2910 extending outwardly from the center of the head2908. As illustrated in this particular embodiment, several projections2910 may form a web or starburst configuration, although otherconfigurations are also possible, and may include further interlinkingof the projections 2910. Each projection 2910 preferably comprises acentral channel 2912 extending along the length of the projection 2910and connected in the center of the suction head 2908. The channel 2912is preferably connected to one or more apertures 2906 disposed along itslength and suitable for suctioning wound exudate from a wound site.Preferably, a centrally-located controlled air leak 2914 communicatingwith the wound site is present, with a filter 2915 to keep particulatesand other contaminants from entering the wound site. The filter 2915 maybe constructed from any suitable material, for example Gore-Tex®. Insome embodiments, at least a portion of the tail 2905 may be providedwith a layer of adhesive on its wound-facing side, which can serve tobetter adhere to patient skin and seal the wound site.

In use, and with continued reference to FIGS. 29A-B, a wound site isprepared and cleaned in substantially the same way as describedpreviously. The suction head 2908 is then trimmed as necessary to fitthe wound site; the trimming may include cutting through the projections2910. If so provided, an adhesive protective layer may be removed fromthe wound-facing side of the tail 2905 to adhere against the patientskin. Subsequently, a drape 2903 may be placed over the suction head2908 and sealed to the skin surrounding the wound. A conduit 2904connected to a source of negative pressure is then connected to the tail2905, thus applying negative pressure to the wound site. When used, thehead 2908 may be designed so that the drape 2903 seals against all orpart of the open ends of the channels 2912 in the projections 2910 whenthe head 2908 is trimmed.

FIGS. 30A-B illustrate an embodiment of a wound treatment system 3001provided with a piercing nozzle 3010. Here, certain embodiments providefor the piercing nozzle 3010 to be mounted or attached to a plate 3008,where the plate 3008 is preferably perforated so as to effectively serveas a distribution manifold for negative pressure to the wound site andas a conduit to channel exudates away from the wound site. In certainembodiments, multiple piercing nozzles 3010 may be provided, and whichmay be distributed over the plate 3008. The piercing nozzle ispreferably designed to have a sharp edge suitable for piercing a drape,for example a drape 3003 placed over a wound site and over the piercingnozzle 3010 and plate 3008, and the nozzle 3010 is also preferablycomprises a conduit or channel therein suitable for conveying fluidand/or negative pressure. In a preferred embodiment, a suction head 3005is provided with at least one aperture 3006 disposed on its wound-facingside. In some embodiments, an adhesive layer may be provided on thewound-facing side of the head 3005 suitable for securing the head 3005to the drape 3003. In additional embodiments, the drape 3003 may bemechanically fastened to the head 3005 by means of features incorporatedon the wound-facing side of the head 3005 suitable for mechanicalfastening of the head 3005 to the drape 3003. The aperture 3006 may bedesigned so as to receive at least part of the piercing nozzle 3010, soas to create a fluidic connection between a wound site and a source ofnegative pressure connected to the head 3005 through the piercing nozzle3010 and the aperture 3006. Some embodiments may also provide acontrolled air leak 3014 optionally provided with a filter andintegrated into the drape 3003; preferably, this air leak 3014 islocated in a region in close proximity to the plate 3008.

With continued reference to FIGS. 30A-B, in use a wound site is preparedsubstantially as described previously. The plate 3008 is preferablyplaced over the wound site area, with the piercing nozzles 3010 facingupward. The drape 3003 is then placed over the wound site and over theplate 3008, and then sealed to the skin surrounding the wound site.Subsequently, the suction head 3005 is pressed over the nozzles 3010,causing the nozzles 3010 to pierce the drape 3003 and be received intothe aperture 3006. The wound site is then connected to a source ofnegative pressure and treated until the wound has attained a selectedstage of healing.

FIGS. 31A-B illustrate an embodiment of a negative pressure treatmentsystem 3101 comprising a suction port which shares some similaritieswith the embodiments described in FIG. 22. In a preferred embodiment,the system 3101 comprises a suction port 3105 integrated with a drape3103. The port 3105 is preferably constructed from a section of foam orother porous material, with its outside surface surrounded by asemi-rigid plastic. In some embodiments, the drape 3103 may be providedpre-attached to the port 3105, for example by adhering the port 3105onto the top side of the drape 3103, or by attaching the port 3105 tothe around and to bottom side of the drape 3103. The port 3105preferably comprises a controlled air leak 3114 which communicates tothe interior of the port 3105. The port 3105 may also comprise anaperture 3106 able to receive a connector 3110 and/or a tube or conduit3104. Preferably, this aperture 3106 is sealed with, for example, a thinlayer of plastic that can be perforated with a connector 3110. Theconnector 3110 is preferably designed with a sharp tip able to pierce alayer of plastic disposed over the aperture 3106, and is able to createa fluid-tight seal between itself and the aperture 3106, for example bymeans of barbs 3111. A removable flap 3116 may also be attached to theport 3105 and made to overlay the aperture 3106 so as to protect theaperture 3106 from damage during handling. The flap 3116 may also bepulled during insertion of the connector 3110 to as to place the drape3103 under tension and facilitate its perforation. To prevent theconnector 3110 and/or tube 3104 from projecting past the port 3105 andpossibly disturbing the wound site, a plate 3107 may be attached orformed with the port 3105. The plate 3107 is preferably constructed froma resilient, harder material such as a plastic and capable of resistingpiercing when pushed by the connector 3110. In order to channel woundexudate from the wound site, the plate 3107 preferably comprises one ormore apertures 3108.

FIGS. 32A-K illustrate embodiments of a negative pressure system 3201.Here, the system 3201 comprises a port 3203 with a layer of adhesive3205 disposed on its underside. This adhesive layer 3205 may be placedover an aperture 3207 on a drape 3202 placed over a wound to secure theport 3203. Alternatively, the port 3203 may be adhered or welded to asmaller drape, optionally provided with a further adhesive layer. Insome embodiments, this port 3203 may be relatively small, for example 17mm across, although other sizes may also be appropriate. The port 3203may be provided with a through opening 3209, preferably located on avertical axis; this opening 3209 may also be provided with a removablecover 3210, which can in turn also function as a controlled air leak3212. Preferably, the air leak 3212 comprises a filter 3213 to preventcontaminants from entering the wound. The opening 3209, preferably whenin a vertical configuration, can be designed to accommodate a cuttingtool 3215 designed to pierce an underlying drape. The port 3203 is alsoprovided with a connection port 3217 to which a tube 3204 may beconnected. In some embodiments, the tube 3204 is pre-assembled to theconnection port 3217.

In use, after adhering the port 3203 over a drape placed over a wound,the removable cover 3210 is removed, and the cutting tool 3215 is pushedthrough the opening 3209 so as to pierce the drape. The cover 3210 isreplaced and the tube 3204 is connected (if necessary) to the port 3203and then connected at its downstream end to the source of negativepressure.

FIGS. 33A-H illustrate embodiments of a negative pressure treatmentsystem 3301 provided with a template 3305. This template 3305 ispreferably provided with a double-sided adhesive layer 3306 on itsbottom-facing side, and comprises one or more cutting guides 3307. Theseguides 3307 may, for example, be in the shape of a cross as illustrated,or may take other forms. The system 3301 also comprises a port 3309which is preferably of a similar size and shape to the template 3305,and which may have a tube 3304 pre-attached to itself. Obviously, someembodiments may instead provide for detachable tube 3304. In onenon-limiting embodiment, the port 3309 measures approximately 25 mmacross.

In use, the template 3305 is used to guide and control the size of thedrape incision. It is placed over a drape 3311, preferably by adheringthe bottom-facing side of the double-sided adhesive layer 3306 to thedrape 3311 (an optional release layer 3312 may also be present).Subsequently, an incision is made through the cutting guides 3307 intothe drape 3311 to create an aperture sufficient for a fluidicconnection. Subsequently, the template 3305 is peeled away from thedouble-sided adhesive layer 3306 (optionally with the aid of a tab 3313)to reveal a top-facing layer of adhesive upon which the port 3309 maythen be attached. Optionally, the double-sided adhesive layer 3306 maybe pigmented to allow the user to easily align the port 3309 on theadhesive layer 3306. Alternatively, the port 3309 may be adhered orwelded to a smaller drape, optionally provided with a further adhesivelayer, and which may then be placed over the aperture formed under theadhesive 3306. Treatment of the wound then proceeds in a similar fashionas to the other embodiments previously described. An advantage of thiscutting template 3303 is that the drape aperture size may be controlledso as to permit the use of a smaller port 3309, and which may beadvantageous in treating smaller wounds.

FIGS. 34A-H illustrate embodiments of a negative pressure treatmentsystem 3401 comprising a port 3403 including a protruding channel 3405disposed on its underside. The channel 3405, and optionally part or theremainder of the port 3403 may be constructed from a soft and pliablematerial, including gels, foams, and combinations thereof such assilicone, polyurethane, polyethylene, polyvinyl chloride, and otherplastics. The protruding channel 3405 may be useful in properlypositioning the port 3403 over an aperture made into a drape 3413, andthe preferably soft and conformable material used to construct itminimizes pressure damage caused by the port and/or channel pressingonto the wound. In some embodiments, the port 3403 measuresapproximately 17 mm across, although larger or smaller sizes may beused. A layer of adhesive 3407 with an optional release layer 3409 arepreferably provided on the underside of the port for attachment to adrape, and the port 3403 should also comprise an opening 3411 so as topermit connection of a tube 3404. In an alternative embodiment, the port3403 may be adhered or welded to a smaller drape, optionally providedwith a further adhesive layer.

In FIGS. 35A-H, embodiments of a negative pressure system 3501 comprisea port 3503 attached to a drape strip 3505. The port 3503 is preferablyconstructed from a soft, conformable material, and includes anattachment port 3507 for a tube 3504 to be connected thereto. Theunderside of the drape strip 3505 has a layer of adhesive 3509,optionally covered by a release layer 3510. In use, the drape strip 3505is adhered directly over a prepared wound, without the use of anadditional drape, but with the wound preferably filled with awound-packing material. If no wound packing material is used, then theadhesive 3509 is preferably chosen to be minimally adherent to woundtissue but sufficiently adherent to the skin surrounding the wound, forexample a water-soluble acrylic adhesive, such that a fluid-tight sealmay be made. After placing the initial drape strip 3505 over the wound,additional drape strips 3506 (typically not provided with a port) areplaced in an overlapping fashion over the wound so as to create afluid-tight seal over the entire wound. If necessary, the drape strips3505 and 3506 are trimmed to fit. Subsequently, the tube 3504 isconnected to a source of negative pressure and treated in a fashion aspreviously described, with wound exudate being carried through anaperture 3508 situated on the underside of the drape strip 3505 andcommunicating with the port 3503. In some embodiments, the drape strip3505 and/or the additional drape strips 3506 measure approximately 20 mmacross, although other sizes may be used.

FIGS. 36A-I illustrate embodiments of a negative pressure treatment3601. Here, a drape 3603 is provided with one or more premade drainagechannels 3605 leading to a drainage hole 3607 preferablycentrally-located on and going through the drape 3603. The drape 3603 isprovided with a layer of adhesive on its underside, optionally protectedby a release layer 3610. In one non-limiting embodiment, the drapemeasures approximately 100 mm on one side. The drainage channels 3605run from the edge of the drape 3603 to the drainage hole 3607, and aredimensioned so as to permit a tube 3604 to be slid into them so as tocreate a fluidic connection with the drainage hole 3607. Preferably,several drainage channels 3605 are provided, with these channels 3605facing different directions on the drape 3603 so as to permit a tube3604 to be connected from different directions. For example, fourdrainage channels 3605 may be provided at right angles to each other asillustrated. Of course, other arrangements are possible, such as a“starburst” configuration with more drainage channels 3605. Preferably,the drainage channels are constructed so as to remain sealed until atube 3604 is inserted into them.

In FIGS. 37A-G, embodiments of a negative pressure treatment system 3701are shown, the system 3701 comprising a drape 3703 and a port 3705connected to a tube 3704. Here, the drape 3703 is preferably constructedfrom a material provided with miniature, self-sealing openings 3707.These openings 3707 may be molded or cut into the drape 3703, and areordinarily fluid-tight. The underside of the drape 3703 as well as theunderside of the port 3705 may be provided with a layer of adhesivecovered by an optional release layer 3709. In an alternative embodiment,the port 3705 may be adhered or welded to a smaller drape, optionallyprovided with a further adhesive layer. Under the application ofnegative pressure, for example through the port 3705, these openings3707 open so as to permit the transmission of negative pressure from theport to the wound space beneath the drape. In other embodiments, theopenings 3707 may act as one-way valves. This drape 3703 has severaladvantages, such as not requiring a separate aperture to be cut into thedrape 3703, while also permitting the port 3705 to be positioned at anyappropriate location on the drape 3703. In some embodiments, the port3705 measures approximately 25 mm across.

FIGS. 38A-I illustrate embodiments of a negative pressure treatmentsystem 3801 which comprise a bayonet connection between a ring 3803 anda port 3805. The port 3805 has one or more tabs 3807 which mate into acorresponding recess 3808 located on the ring 3803, which in someembodiments may have a diameter of approximately 35 mm. The ring 3803also includes a groove (not illustrated) adjoining the recess 3808 andconfigured to receive the tab(s) 3807 and thus create a fluid-tightconnection. The ring 3803 preferably comprises an adhesive layerdisposed on its underside (optionally protected by a release layer3811), which may be used to secure it to a drape. In an alternativeembodiment, the ring 3803 may be adhered or welded to a smaller drape,optionally provided with a further adhesive layer. The port 3805 has aconnector 3809 configured to connect to a tube 3804. In use, the ring3803 is placed and preferably adhered over an incision 3812 made on adrape 3813 placed over a wound. Subsequently, the port 3805 ispositioned over the ring 3803 so that the tab 3807 may fit into therecess 3808. Once so positioned, the port is rotated, for example byfrom 30 to 90.degree., so that the tab 3807 slides into the grooveadjoining the recess 3808 so as to create a fluidic seal. The user maytherefore choose the orientation in which the tube connector 3809 pointsirrespective of the orientation of the ring 3803.

Turning now to FIGS. 39A-B, one embodiment of a negative pressuretreatment system 3901 uses a low-profile port 3903 configured to attachto a one-way valve 3905 (which can for example be a reed or flap valve)attached to a drape 3907. In some embodiments, the one-way valve 3905may be pre-attached to the drape 3907 prior to placing it over a wound.In other embodiments, the valve 3905 is attached onto the drape 3907after the drape has been placed over the wound and an incision oraperture made into it, or else the valve 3905 in incorporated into aport that is provided pre-attached or welded to a drape. The port 3903preferably comprises one or more air leaks 3909, which are of a similardesign to those illustrated in other embodiments herein. A tube 3904 maybe attached to the port 3903.

FIG. 40 illustrates an embodiment of a negative pressure treatmentsystem 4001 that is somewhat similar in operation to the embodimentillustrated in FIGS. 24A-B. Here, a low-profile fluidic connector 4003may be slid under a drape 4005 situated over a wound. The connector 4003comprises a suction head 4007 at its distal end, and has an adaptor 4009at its proximal end configured to connect to a tube 4004. At theboundary of the drape an air leak filter 4011 may be placed next to theconnector 4003 to permit for controlled air flow into the wound space.The filter 4011 may either be attached to the connector 4003 to allowfor air flow into the interior channel of the connector 4003 or else maybe configured to let air into the wound space without going through theconnector 4003. In an alternative embodiment, the fluidic connector 4003may be adhered or welded to the drape 4005 prior to use.

FIG. 41A illustrates an embodiment of a negative pressure treatmentsystem 4101 comprising a suction adapter 4103 placed underneath a drape4105. The suction adapter 4103 comprises a plurality of tubes 4106 so asto create a suction manifold that may be useful in distributing negativepressure while reducing the overall height of the adapter 4103, a usefulaspect for low-profile conformable suction adapters. At the proximal endof the adapter 4103, a converging point 4107 connects to all of thetubes 4106 and connects to a single tube 4104 connected to a source ofnegative pressure. In some embodiments, an air leak 4109 may be providedon the adapter 4103, for example over the converging point 4107.Preferably, a seal 4111 can be provided at the junction where the tubes4106 meet the drape 4105. Such a seal 4111 may be either integrated ontothe tubes 4106, either in a fixed or slideable configuration, or elseplaced separately. The material used for the seal 4111 may be aclosed-cell foam wedge, but any material capable of creating a fluidtight seal can be used. FIG. 41B illustrates a section taken along theline A-A illustrating how in some embodiments, the tubes 4106 can be ofa very low height, which may be advantageous for example in minimizingpatient discomfort. In some embodiments, the seal 4111 and the tubes4106 are attached or welded to the drape 4105 to form a single unit.

In FIGS. 42A-B, an embodiment of a negative pressure treatment system4201 comprises a drape 4203 with an aperture 4205 integrated into it.The aperture 4205 has an area 4206 coated with a layer of adhesive andmay optionally be protected by a release layer 4207. The aperture 4205may also comprise a controlled air leak 4209, preferably provided with afilter to prevent entry of pathogens and contaminants. A port 4211 isalso part of the system 4201, and may comprise a connector 4212 toconnect to a tube 4204. On the underside of port 4211, an adhesive layeroptionally protected by a release layer 4213 may also be present. Inuse, the drape 4203 is placed over a wound with the aperture 4205preferably located in a central position. Subsequently, the releaselayer 4207 is removed to expose an adhesive layer. Next, the port 4211,optionally following the removal of a release layer 4213, is adhered tothe area 4206 so as to create a fluidic connection between the port 4211and the aperture 4205.

FIGS. 43A-B illustrate an embodiment with a piercing point sharing somesimilarities to the embodiment described in FIGS. 13A-B. Here, anembodiment of a negative pressure treatment system 4301 comprises a port4303 provided with one or more piercing tips 4305. Preferably, thispiercing tip 4305 is located on the top inner surface of the port 4303over an aperture 4307. In use, the application of vacuum through a tube4304 to the port 4303 draws a portion 4309 of a drape 4308 placed over awound into the aperture 4307. The piercing tip 4305 then pierces thedrape portion 4309 so as to create a fluidic connection between thewound space and the source of negative pressure so as to permit woundexudate to be removed from the wound. Other aspects of the port 4303 aresimilar to embodiments described elsewhere herein, and the port maycomprise a controlled air leak 4311 and a layer of adhesive 4312disposed on the underside of the port 4303.

FIGS. 44A-B illustrate an embodiment of a negative pressure treatmentsystem 4401 comprising a drape 4403 with an integrated suction port4405. Here, the suction port 4405 is preferably constructed of a soft,conformable material which may in some embodiments be the same as thematerial used in the drape 4403. There is preferably a layer of adhesivedisposed on the underside of the drape 4403 so as to permit adherence tothe skin surrounding the wound. The port 4405 may be constructedseparately and adhered or welded to the drape 4403, or in otherembodiments the port 4405 may comprise a channel integrated onto thedrape 4403 so as to form a single unit. At the proximal end of the port4405, a connector 4406 is preferably provided so as to permit theconnection of a tube 4404 to the system 4401. The drape 4403 may alsocomprise an air channel 4407 to permit air to enter the dressing,preferably at a controlled rate. This air channel 4407 can also comprisea filter to prevent contaminants from entering the wound.

In FIGS. 45A-C, an embodiment of a negative pressure treatment system4501 comprises a drape 4503 with a port 4505 integrated thereto. Thedrape 4503 may also comprise cross-linked air channels 4507; suchchannels 4507 communicate with the wound space below the drape 4503 (forexample via through holes 4508) so as to permit a controlled air flowrate to the wound. The edges of the drape 4503 provide openings for thecross-linked air channels 4507, and the drape 4503 may be cut to sizewithout significantly interfering with the function of the air channels4507. In some embodiments, however, it may be advantageous to use afilter or filtering element in conjunction with the air channels 4507 toprevent contaminants from entering the wound space. Preferably, anadhesive layer is disposed underneath the drape 4503. In one embodiment,the port 4505 comprises a domed portion 4509 approximately centered onthe drape 4503. This domed portion 4509 forms a channel for theevacuation of wound exudate together with an elongated portion 4512,which communicates to a fluidic adapter portion 4513 connecting to atube 4504. As with other embodiments described herein, the port 4505 ispreferably constructed from a soft, conformable material (while beingable to maintain patency sufficient to draw out fluid under negativepressure), and may be either integrated to the drape 4503 as a singleunit (e.g., by molding) or constructed from multiple pieces laterattached or joined together.

FIGS. 46A-B illustrate an embodiment of a negative pressure woundtreatment system 4601 that comprises one or more suction channels 4603integrated into an impermeable cover 4605. The one or more suctionchannels 4603 may enter into the cover 4605 to form a network ofconduits surrounding a central air leak 4609, preferably provided with afilter. Of course, alternative configurations are possible, such as afan- or net-shaped system of channels 4603, and the air leak 4609 may insome embodiments be omitted or placed in a different location. Thechannels 4603 converge onto a central collector 4607, which connects toa tube 4604 that may be connected to a source of negative pressure. Thecover 4605 is preferably constructed of a fluid-impermeable material,and is preferably sufficiently thick so as to be able to integrate thechannels 4603 within itself. Preferably, a layer of adhesive is disposedon its underside. An example of a suitable material for the cover 4605may include a closed-cell foam. In some embodiments, spaces may be madeinto the cover 4605 into which the channels 4603 connect to. In otherembodiments, the channels 4603 continue into the cover 4605 and thecover 4605 is, for example, molded around the channels 4603. In use, thesystem 4601's cover 4605 may be trimmed to size if necessary (whileavoiding cutting through the channels 4603) and placed over a woundsite, optionally filled with a wound packing material, and adhered tothe skin surrounding the site. Subsequently, a source of suction may beapplied to the wound and exudates removed through the channels 4603.

Turning now to FIGS. 47A-B, an embodiment of a negative pressuretreatment system 4701 comprises a low-profile suction unit 4703 coveredwith a membrane 4707. In some embodiments, the suction unit 4703 may beconstructed from open-cell foam. Embedded within the suction unit 4703is a tube 4704. This tube 4704 may be fenestrated or perforated so as tohelp prevent clogging and apply suction over a larger area. The tube4704 passes through an impermeable section 4705. This impermeablesection 4705 may be constructed, for example, from a closed-cell foam,and is attached to the suction unit 4703. In some embodiments, theimpermeable section 4705 may be molded around the tube 4704. Althoughthe tube 4704 may be connected directly to a source of negativepressure, it may in some embodiments be advantageous to provide aconnector situated proximally to the tube 4704 to permit connection ofanother tube in communication with a source of negative pressure. Themembrane 4707 may be constructed in several parts, or may be one largesheet. Preferably, it is provided with a layer of adhesive on itsunderside, optionally protected by a release layer 4709 which covers theportions of adhesive not secured to the suction unit 4703 and/or theimpermeable section 4705. In use, the system 4701 may be positioned overa wound, optionally filled with packing material. Then, the releaselayer 4709 is removed so as to permit the membrane 4707 to be adhered tothe skin surrounding the wound. Negative pressure is then applied to thewound through the tube 4704.

FIGS. 48A-E illustrate an embodiment of a negative pressure treatmentsystem 4801 comprising a flexible suction adapter sheet 4803 capable ofbeing packed into a wound space. The sheet 4803 preferably comprises alarger, planar section 4805 at its distal end, connected to a tailportion 4806 at its proximal end. At the proximal end of the tailportion 4806, a connector 4807 may be provided to permit a tube 4804 tobe connected thereto. The planar section 4805 may be comprised of twolayers: a bottom layer 4810 and a top layer 4811. The bottom layer 4810comprises one or more perforations 4812 that face toward the wound so asto collect wound exudate and distribute negative pressure to the wound.The top layer 4811 comprises a network of channels 4813 communicatingwith the perforations 4812, and fluidically link to the source ofnegative pressure so as to channel wound exudate to the source ofnegative pressure. In some embodiments, the channels 4813 form aninterconnected network (such as in a grid configuration), which may beadvantageous in preventing clogging and permitting negative pressure tobe distributed to the entire bottom layer 4810 in spite of folding thatmay occur when the portion 4805 is placed within a wound. In someembodiments, the tail portion 4806 can comprise a layer of adhesive onits wound-facing side, which may be useful in forming a seal with theunderlying skin. The sheet 4803 may also be covered with a flexibledrape 4815 to provide an additional, substantially air-tight seal overthe wound.

In use, a wound is cleaned, and the planar section 4805 is inserted intothe wound so as to function as a wound packing material. Preferably, thebottom layer 4810 is placed facing into the wound. Subsequently, thetail portion 4806 may be adhered to the skin surrounding the wound. Adrape 4815 is then placed and sealed over the entire wound, followed byconnecting the tube 4804 to a source of negative pressure.

In FIGS. 49A-B, a negative pressure treatment system 4901 may comprise awound packing pouch 4903 used with a port 4905 and a drape 4907. Thepouch 4903 is a flexible pouch that may be filled with a conformablefiller 4909, for example granular beads, and may be placed into thewound space as a filler. The pouch 4903 also comprises a semi-permeableor perforated membrane 4910 containing the filler 4909. In use,different size pouches 4903 may be supplied, or multiple pouches 4903may be used to fill the wound space as desired. The port 4905 is similarto other ports described herein, and comprises a distal head portion4913 designed to be placed in contact with the pouch 4903 so as toevacuate wound exudate and communicate negative pressure to the pouch4903. In an alternative embodiment, this port 4905 may be adhered orwelded to a smaller drape, optionally provided with a further adhesivelayer. At the proximal end of the port 4905 is a connector 4915configured to connect to a tube 4904. In some embodiments, thisconnector 4915 may comprise a piercing or chisel tip configured topierce through the drape 4907, which may be advantageous in making aneasier connection to the tube 4904. The drape 4907 may be provided withan adhesive layer on its wound-facing side, and provides an essentiallyfluid-tight seal over the wound space and over the pouch 4903. In someembodiments, the drape 4907 may be provided with a controlled air leak4917, optionally protected with a filter, designed to permit acontrolled amount of air into the wound.

FIGS. 50A-C illustrate embodiments of a negative pressure treatmentsystem 5001 comprising a sealing port 5003. Here, the port 5003comprises a distal head portion 5005 and a proximal tail portion 5006.The tail portion 5006 includes a connector 5007 configured to connect toa tube 5004. The head portion 5005 comprises an outer vacuum ring 5009;this ring 5009 may in some embodiments be used to seal the port 5003against the skin surrounding a wound, and may be useful in smaller-sizedwounds that the ring 5009 is able to circumscribe. In other embodimentsand for larger wounds, a drape may be used in a manner similar to otherembodiments described herein. In use, a slot 5011, or a series ofapertures on the underside of the ring 5009 permits negative pressuretransmitted into the ring 5009 to seal the ring 5009—and thus the entireport 5003—against the skin of a patient. The head portion 5005 alsocomprises a central region 5011 that applies a portion of the vacuumfrom the vacuum source to the wound and evacuates wound exudate (theremainder of the vacuum is applied to the skin surrounding the wound bythe ring 5009). Here, the region 5011 may also comprise an air leak5013, for example disposed centrally and with an optional air filter5014. In some embodiments, a separate channel 5015 may be present tochannel the air drawn into the wound and port 5003 downward and into thewound space. Preferably, such a channel 5015 is configured to makecontact with any wound packing material placed into the wound.

FIGS. 51A-B illustrates an embodiment of a negative pressure woundtreatment system 5101 comprising a low-profile suction adapter 5103configured to be placed over a wound. The suction adapter 5103preferably comprises a vacuum portion 5105 and a controlled air leakportion 5106, wherein both of these portions 5105, 5106 are preferablyconstructed of a flexible, soft material capable of transmitting air andfluid flow through themselves. Examples of such materials may includeopen-cell foams. The entire suction adapter 5103, including the portions5105, 5106, is preferably covered on its upper portions with aliquid-impermeable membrane 5108. The vacuum portion comprises at itsproximal end a connector 5107 for connecting to a tube 5104. Thecontrolled air leak portion 5106 preferably comprises an open end 5109not covered by membrane 5108 so as to permit a flow of air into theadapter 5103. Preferably, a filter is disposed over this end 5109 toprevent the entry of contaminants into the wound space. In thisembodiment, strips of tape 5111 are used to seal the edges of themembrane 5108 against the skin of a patient. In other embodiments, someor all of the underside of the 5108 may be covered in a layer ofadhesive. Preferably, the system 5101 is used on a wound that has beenfilled with a wound packing material such as foam or gauze.

In FIGS. 52A-B, a negative pressure treatment system 5201 comprises abladder 5203 in combination with a suction adapter sheet 5205 and adrape 5207. The bladder 5203 may be filled with a fluid such as air orwater, and may be secured to the wound for example by straps 5209,although other means sufficient to apply positive pressure on the woundmay be used. Under the bladder 5203 is the drape 5207, which ispreferably liquid-impermeable and coated with a layer of adhesive on itswound-facing side. The suction adapter sheet 5205 is below the drape,and may be of a type similar to the embodiment described in FIG. 48A.Preferably, this sheet 5205 comprises one or more conduits configured tochannel wound exudate toward a source of negative pressure whiledistributing negative pressure over the entire wound area. The proximalportion 5206 of the sheet 5205 may comprise a connector 5210 suitablefor connecting to a tube 5204. Optionally, the space below the suctionadapter sheet 5205 is filled with a wound packing material such as anopen-cell foam. Such a wound treatment system 5201 may be beneficial foruse on wounds that require additional positive pressure upon the woundbed. Additionally, use of an embodiment with the straps 5209 may bebeneficial for use in particular on the legs and arms of a patient.

FIGS. 53A-D show variations of the bladder system described in FIG. 52A.Here, the negative pressure wound treatment system 5301 comprises abladder 5303 placed underneath a drape 5305. The bladder 5303 may befilled with a fluid such as saline solution, although other fluids suchas air may be used. In some embodiments, a layer of wound contactingmaterial 5307 may be placed in contact with the wound. This woundcontacting material 5307 may be foam, gauze, or other suitablematerials. Preferably, this material 5307 forms a thin layer and ispushed into contact with the wound. Subsequently, the bladder 5303 isplaced into the wound so as to fill the remainder of the wound space.The drape 5305 is then placed over the bladder 5303 and wound contactingmaterial 5307 and sealed to the skin surrounding the wound. An aperture5309 may then be made into the drape 5305 (although the drape may beprovided with an aperture already made into it) over a portion of thewound where the wound contacting material 5307 is in contact with thedrape 5305, and a suction adapter 5311 placed over the aperture 5309.Alternatively, the suction adapter 5311 may be adhered or welded to thedrape 5305 or a smaller drape, optionally provided with a furtheradhesive layer. The adapter 5311 may be connected to a source ofnegative pressure via a tube 5304 connected to its proximal end. In someembodiments, the drape 5305 may also be provided with a controlled airleak 5313, which is in some cases covered with a filtration element toprevent contaminants from entering the wound.

In FIG. 54A, an embodiment of a negative pressure wound treatment system5401 is illustrated that uses a wound packing material 5403 provided indiscrete portions. The wound packing material 5403 may be supplied inthe form of a roll 5405, for example as illustrated in FIG. 54B, anddispensed as necessary to fill a wound space; individual sections may bedetached, or long sections may be packed into the wound. The woundpacking material 5403 may be comprised of a porous material such asopen-cell foam, or any other material capable of transmitting negativepressure to the wound site. The form of the wound packing material 5403may be achieved by molding or heat-forming the material. Alternatively,it may be fabricated using nets or films to join the individualsections. In a further embodiment, the wound packing material 5403 maybe molded from solid polymers, and channels may be formed onto thesurface to allow removal of fluids from the wound tissue. After a woundis filled with the wound packing material 5403, a drape 5407 (optionallyprovided with an integrated air leak 5408 similar to those previouslydescribed herein) is placed over the wound and sealed to the skinsurrounding the wound. An aperture is then made into the drape 5407sufficient to permit a port 5409 to be placed over it so that woundexudate may be removed from the wound site through a tube 5404 connectedto the port 5409. Alternatively, the port 5409 may be adhered or weldedto a smaller drape, optionally provided with a further adhesive layer orelse the drape 5407.

FIGS. 55A-J illustrate embodiments of a negative pressure woundtreatment system 5501 similar to the embodiments illustrated in FIG.15A. Here, the system 5501 may comprise a bridge 5502 having a proximalend 5503 and a distal end 5505 and an applicator 5520 at the distal end5505 of the bridge 5502 forming a flexible suction adapter. Preferably,the system 5501 is constructed in a similar fashion to the system 1501,and may comprise a bridge 5502 constructed from a similar dual layerarrangement as previously described. A connector 5504 is preferablydisposed at the proximal end 5503 of the bridge 5502, so as to connectto at least one of the channels 5512 and/or 5516, as shown in FIG. 55D.A cap 5536 may be provided with the system 5501 (and can in some cases,as illustrated, be attached to the connector 5504). The cap 5536 can beuseful in preventing fluids from leaking out of the proximal end 5503.The system 5501 may include a source of negative pressure such as a pumpor negative pressure unit 5534 capable of supplying negative pressure.The pump also preferably comprises a canister or other container for thestorage of wound exudates and other fluids that may be removed from thewound. In some embodiments, this pump 5534 can be a RENASYS GO pump, assold by Smith & Nephew. The pump 5534 may be connected to the connector5504 via a tube 5540. In use, the applicator 5520 is placed over anaperture 5535 formed in a drape 5531 that is placed over asuitably-prepared wound 5530, which may in some cases be filled with awound packing material such as foam or gauze. Subsequently, with thepump 5534 connected via the tube 5540 to the connector 5504, the pump isactivated, thereby supplying negative pressure to the wound. Applicationof negative pressure may be applied until a desired level of healing ofthe wound 5530 is achieved.

Here, and with particular reference to FIGS. 55C-D, the system 5501 maycomprise a bridge 5502 having a proximal end 5503 and a distal end 5505and an applicator 5520 at the distal end 5505 of the bridge 5502. Insome embodiments, the bridge 5502 may comprise an upper channel layer5512 positioned between an upper layer 5510 and an intermediate layer5514, with a lower channel layer 5516 positioned between theintermediate layer 5514 and a bottom layer 5518. Preferably, the layers5510, 5514, and 5518 have elongate portions extending between proximaland distal ends and may be comprised of a material that isfluid-impermeable, for example polymers such as polyurethane. It will ofcourse be appreciated that the layers 5510, 5514, and 5518 may each beconstructed from different materials, including semi-permeablematerials. As illustrated in FIG. 55D, the upper and lower layers 5510and 5518 may be curved, rounded or outwardly convex over a majority oftheir lengths. During assembly, for example, the layers 5510, 5514, and5518 may be pinched together to weld or adhere the layers together. Indoing so, the proximal ends of the channels 5512 and 5516 may besandwiched between these layers, thus partially compressing the proximalends of the channels 5512, 5516 and stretching the layers 5510, 5514,5518 over these aforementioned proximal ends. Of course, the proximalends of the materials used in the bridge section 5502 may notnecessarily be rounded or curved; as shown in FIG. 55J, they can remainsubstantially squared off and straight.

Similarly to the embodiment described in FIG. 6 with regards to thespacer 609, the upper and lower channel layers 5512 and 5516 arepreferably elongate layers extending from the proximal end 5503 to thedistal end 5505 and may each preferably comprise a porous material,including for example open-celled foams such as polyethylene orpolyurethane. In some embodiments, one or more of the upper and lowerchannel layers 5512 and 5516 may be comprised of a fabric, for example aknitted or woven spacer fabric (such as a knitted polyester 3D fabric,Baltex 7970®, or Gehring 879®) or a nonwoven material. Suitablematerials may also include terry-woven or loop-pile materials. Thefibers may not necessarily be woven, and can include felted and flocked(including materials such as Flotex®) fibrous materials. The materialsselected are preferably suited to channeling wound exudate away from thewound and for transmitting negative pressure and/or vented air to thewound site, and may also confer a degree of kinking or occlusionresistance to the channel layers 5512 and 5516 as described below. Inone embodiment, the upper channel layer 5512 may comprise an open-celledfoam such as polyurethane, and the lower channel layer may comprise afabric as described herein. In another embodiment, the upper channellayer is optional, and the system may instead be provided with an openupper channel. In the embodiment illustrated in FIG. 55D, the upperchannel layer 5512 may have a curved, rounded or upwardly convex uppersurface and a substantially flat lower surface, and the lower channellayer 5516 may have a curved, rounded or downwardly convex lower surfaceand a substantially flat upper surface.

In some embodiments, the fabric may have a three-dimensional (3D)structure, where one or more types of fibers form a structure where thefibers extend in all three dimensions. Such a fabric may in some casesaid in wicking, transporting fluid, and/or transmitting negativepressure. To prevent the channels 5512 and/or 5516 from being displacedor twisted while encased in the system 5501—which may impair performanceof the respective channels under negative pressure—it may in someembodiments be preferable to adhere or otherwise secure the channels5512 and/or 5516 to one or more of the layers 5510, 5514, and 5518. Incertain embodiments, these materials remain open and capable ofcommunicating negative pressure to a wound area under the typicalpressures used in negative pressure therapy, for example between 40 to150 mmHg, although higher and lower values are possible. In someembodiments, the fabric may comprise several layers of material stackedor layered over each other, which may in some cases be useful inpreventing the channel 5516 from collapsing under the application ofnegative pressure. In other embodiments, the fabric used in channel 5516may be between 1.5 mm and 6 mm; more preferably, the fabric may bebetween 3 mm and 6 mm thick, and may be comprised of either one orseveral individual layers of fabric. In other embodiments, the channel5512 may be between 1.2-3 mm thick, and preferably thicker than 1.5 mm.Additionally, and as described previously, the materials used in thesystem 5501 are preferably conformable and soft, which may help to avoidpressure ulcers and other complications which may result from a woundtreatment system being pressed against the skin of a patient. Furtherexamples of 3D fabrics are discussed below in FIGS. 56A-C.

Preferably, the distal ends of the layers 5510, 5514, and 5518 and thechannel layers 5512 and 5516 are enlarged at their distal ends (to beplaced over a wound site), and may form a “teardrop” or other enlargedshape. The distal ends of at least the layers 5512, 5514, 5516, and 5518may also be provided with at least one through aperture. This aperturemay be useful not only for the drainage of wound exudate and forapplying negative pressure to the wound, but also during manufacturingof the device, as these apertures may be used to align these respectivelayers appropriately.

With additional reference to FIGS. 55D-E and J, a channel connector 5506is provided at the proximal end 5503 of the bridge 5502, the channelconnector 5506 preferably being configured so as to be embedded into thelower channel layer 5516 so as to create a secure fluidic connection.The channel connector 5506 may in some embodiments be inserted into apre-made cavity formed into the channel 5516; as illustrated in FIG.55J, this cavity can be cut out or can be in the form of a rabbet joint.In some embodiments, the channel connector 5506 may be one of theconnectors described in FIGS. 57A-B below. With one end of the channelconnector 5506 being embedded into the lower channel layer 5516, theother end of the channel connector 5506 may be connected or incommunication with, in one embodiment, a connector tube 5507, althoughin some embodiments the channel connector 5506 may be connected directlyto the connector 5504, or else connected directly to a tube 5540connected to a source of negative pressure. When using a connector tube5507, the resulting assembly can permit a connector 5504 to be attachedthereto. A cap 5536, which may be secured to the suction adapter forexample via a cap leash 5527 secured with a ring disposed on the outersurface of the connector tube 5507. The cap 5536 may be used to coverthe end of the suction adapter, for example at the connector 5504, so asto prevent exudate and other wound fluids from leaking out. Theconnector 5504 is preferably configured to connect with a tube 5540connected to a source of negative pressure. The connector 5504 may forexample comprise a lip or other such structure to aid in securing theconnector 5504 to a tube 5540 and/or cap 5536, although it will beunderstood that other connector types are possible, includingquick-disconnect couplings, luer locks, Christmas-tree, and other suchconnectors.

The upper layer 5510 may comprise additional material extendingdownward, preferably at least of the thickness of the bridge 5502; thismaterial may then be used to bond or weld to the other layers so to forma fluid-tight seal. More specifically, during assembly, the upper layer5510 may be attached, for example by melting, welding, or withadhesives, to the lower layer 5518 so as to form a fluid-tight seal(with the exception of the apertures at the distal and proximal ends).Preferably, the middle layer 5514 is attached to the top layer 5510 andthe bottom layer 5518. In some embodiments, it may be preferable toattach or bond the connectors 5504 and/or 5506, as well as the tube 5507to at least one of the layers 5510, 5514, 5518 so as to create afluid-tight connection. To provide for a more secure connection, someembodiments may also be provided with a weld 5532 made onto the lowerlayer 5518. The lower channel 5516 may have a hole or aperture madethrough it, which may be used to weld it, via the weld 5532, to thelower layer 5518. This welding of the lower channel 5516 to the lowerlayer 5518 via the weld 5532 made through the hole 5533 may thus aid inpreventing the various layers and channels from shifting or beingdisplaced. Obviously, it will be understood that other securement meansmay be used, for example adhesives and the like, and that sucharrangements may be also be used in the upper channel 5512.

In certain embodiments, for example as illustrated in FIGS. 55C-J, acontrolled air leak 5524 may be disposed on the bridge portion 5502, forexample at the proximal end thereof. This air leak 5524 may comprise anopening or channel extending through upper layer 5510, such that the airleak 5524 is in fluidic communication with the upper channel 5512. Uponthe application of suction to the system 5501, air will enter throughthe air leak 5524 and move from the proximal end 5503 to the distal end5505 along the upper channel 5512. The air will then be suctioned intothe lower channel 5516 by passing through the apertures through thedistal ends of the layers 5512, 5514, 5516 and 5518. The air leak 5524preferably comprises a filter 5525, which may be similar in function tothe filter 521 illustrated in FIG. 5A. Preferably, the air leak 5524 islocated at the proximal end of the bridge portion 5502 so as to minimizethe likelihood of wound exudate or other fluids coming into contact andpossibly occluding or interfering with the air leak 5524 or its filter5525. In some embodiments, this filter 5525 is a microporous membranecapable of excluding microorganisms and bacteria, and which may be ableto filter out particles larger than 45 .mu.m. Preferably, the filter5525 can exclude particles larger than 1.0 .mu.m, and more preferably,particles larger than 0.2 .mu.m. Advantageously, some embodiments mayprovide for a filter 5525 that is at least partiallychemically-resistant, for example to water, common household liquidssuch as shampoos, and other surfactants. In some embodiments,reapplication of vacuum to the system 5501 and/or wiping of the exposedouter portion of the filter 5525 may be sufficient to clear any foreignsubstance occluding the filter 5525. The filter 5525 may be composed ofa suitably-resistant polymer such as acrylic, polyethersulfone, orpolytetrafluoroethylene, and may be oleophobic and/or hydrophobic. Insome embodiments, the filter 5525 may also comprise a supporting backinglayer, for example a nonwoven polyester support. Preferably, the airleak 5524 will supply a relatively constant air flow that does notappreciably increase as additional negative pressure is applied to thesystem 5501. In embodiments of the system 5501 where the air flowthrough the air leak 5524 increases as additional negative pressure isapplied, preferably this increased air flow will be minimized and notincrease in proportion to the negative pressure applied thereto.

The filter 5525 provided in the controlled air leak 5524 in certainembodiments may be useful in a system 5501 for use with more ambulatoryand active patients. For example, a chemically-resistant filter maypermit a patient to bathe or shower without damaging the filter'sfunctionality when reconnected to a source of negative pressure. Anyocclusion or fluid blocking the air leak 5524 could then be cleared by,for example, wiping off the filter 5525 or re-applying negative pressureto the system 5501. Such a system would also have the advantage that thesystem 5501 and any assorted wound dressing materials, if present, wouldnot need to be removed and then re-applied should a patient need to bedisconnected from the source of negative pressure, for exampleincidental to bathing. This would entail significant advantages inimproving the cost-effectiveness and ease of use of the presenttreatment system.

The system 5501 is preferably constructed so as to provide a consistentfluid flow even if the system 5501 is kinked or weighted down. Forexample, in use on a patient, the bridge portion 5502 may become foldedover itself, or else the patient may roll over, thus placing his or herweight over at least a portion of the system 5501. Typically, prior artdressings and fluidic connectors become blocked or ineffective in suchsituations and in some cases may contribute to complications such aspressure ulcers. Here, however, certain embodiments provide for improvedblockage resistance if kinked or weighed down. Preferably, by employingchannel layers 5512 and 5516 as described above, and more preferably byemploying a foam channel layer 5512 and a fabric channel layer 5516, thesystem 5501 is able to maintain a flow rate through the air leak 5524 ofat least 0.08 L/min, and preferably 0.12 L/min while negative pressureis applied through a source of negative pressure. Further embodimentsalso provide for the system 5501 to be able to handle fluid exudatedrainage from the wound site through the lower channel 5516 of at least10 L/day, or 6.9 ml/min. Certain embodiments provide for the system 5501to maintain these flow rates with a weight, for example a 12 kg weight,pressing down on the bridge portion through a rod with a 1 in. diameter.In some embodiments, these flow rates are also maintained while thebridge portion 5502 is kinked over itself with the same weight, or forexample with a 4.75 kg weight placed directly on the folded region. Itis preferable that the system 5501 be able to withstand being folded orkinked over even during an extended period of time, for example over 40hours, and not show any degradation in performance (e.g., flow rates)compared to its performance prior to being folded or kinked over.Preferably, embodiments of the system 5501 are also able to transmit andmaintain a negative pressure at the wound that is close to the negativepressure level at the source of negative pressure. For example, anacceptable level of pressure maintained at the wound may be within.+−0.25 mmHg of the negative pressure set at the source of negativepressure, with this pressure being preferably maintained at this levelwithin 95% of the time that the system 5501 has negative pressureapplied to it. Acceptable pressure levels may include pressure rangesbetween 40-120 mmHg, although levels of 200 mmHg have successfully beenused.

With additional reference to FIGS. 55A-D, G-J, the system 5501 alsocomprises an applicator 5520 designed for placement over a wound site.Preferably, the applicator 5520 comprises a flexible layer 5550, forexample polyethylene or polyurethane, with a layer of adhesive on itslower (wound-facing) side. Optionally, a protective release layer 5529may be placed on the adhesive layer, which is removable before use. Insome embodiments, a more rigid removable backing layer 5552 may beprovided on the upper side of the applicator 5520 to facilitate handlingof the applicator 5520 due to the flexibility of the layer 5550. Theapplicator 5520 preferably comprises an attachment point for the bridge5502 at the distal end 5505, for example using a section of double-sidedadhesive tape 5528. The double-sided adhesive tape 5528 may be protectedby an additional protective release layer, which is removed prior toadhering the bridge 5502 to the applicator 5520. It will be understoodthat different attachment methods are also contemplated, for exampleheat sealing, welding, or suitable adhesives. Some embodiments may alsopermit the manufacture of the bridge 5502 and the applicator 5520 as asingle unit that does not require separate attachment means. Theapplicator 5520 preferably comprises at least one aperture 5526 throughitself and designed to be placed over a wound site, and which can serveto fluidically connect the wound site to the source of negative pressureand to the air leak while also serving as a conduit to draw out woundexudate from the wound site.

In use, and with reference to FIGS. 55A-B, the system 5501 may be usedin a similar fashion to the other embodiments previously disclosedherein. A wound site 5530 is preferably cleaned and prepared in asuitable fashion, and a wound packing material, if necessary, placedinto the wound site, followed by a drape 5531. An aperture 5535 throughthe drape to the wound site is then created, although some embodimentsmay have a pre-made aperture 5535. Subsequently, an operator may situatethe applicator portion 5520 over the aperture 5535. After removing thebacking layer 5529 (if present) from the adhesive layer on the undersideof the applicator portion 5520, the applicator is sealed to the drape5531, and the backing layer 5552 (if present) is also removed from theapplicator portion 5520. A fluidic conduit such as a tube 5540 may thenbe connected to the connector 5504. The tube 5540 may also be connectedto connector 5504 prior to applying the applicator to the wound site.The fluidic conduit is connected to a source of negative pressure 5534,preferably with a container suitable for containing wound exudateinterposed therebetween. The application of negative pressure may thenbe effectuated to the wound site 5530 until the wound site progresses toa desired level of healing.

During use of the system 5501, wound exudate from the wound site 5530 isdrawn by the negative pressure through the lower channel layer 5516. Theair leak 5524 allows air to pass through the upper channel layer 5512into the apertures through the distal ends of the layers 5512, 5514,5516 and 5518. The negative pressure draws air passing through the upperchannel layer into the lower channel layer 5516 back toward the sourceof negative pressure or pump. In some embodiments, the controlled airleak 5524 provides a constant flow of air through the system 5501, whichthen may be used to determine whether blockage or leakage is present.Causes of blockage can include, for example, situations where the lowerchannel 5516 becomes occluded with wound debris. Leakage causes caninclude, for example, improper sealing of the drape over the wound site,or physical damage to the system 5501 leading to excess air leaking intothe system. The blockage or leakage may be determined, in certainembodiments, by measuring the speed of the pump while the pump works tomaintain a constant negative pressure. Pump speed may also be measuredindirectly by measuring the amount of voltage or signal sent to thepump.

FIGS. 56A-C illustrate views of a 3D fabric that may be used in variousembodiments described herein, for example the bridge 5502 of the suctionadapter illustrated in FIGS. 55A-J. Although other porous materials suchas foam may be used in the embodiments described herein, for example inthe upper and lower channels 5512 and/or 5516 illustrated in FIGS.55A-C, the use of 3D fabrics may be advantageous in some circumstances.Certain 3D fabrics have been found to perform well in conveying negativepressure to and wound exudate from a fluidic suction adapter, even whileunder compression—for example when a patient's weight is placed directlyupon the suction adapter, or when negative pressure is applied and/orwhen the fluidic suction adapter is kinked or folded. Some 3D fabricsthat have been found to perform acceptably include knitted polyester 3Dfabric, Baltex 7970®, Gehring 879®, or Coolmax®. Of course, other fibersand fabric types may be used in part or in whole to make 3D fabrics, andinclude without limitation polyamides such as nylon, viscose, cotton, aswell as other synthetic microfibers. 3D fabrics may also be constructedat least in part from fibers such as Nomex® and Kevlar®. Other types offabrics and materials disclosed elsewhere herein may also be used.

In one embodiment, as illustrated in FIGS. 56A-C, the 3D fabric maycomprise a bottom side 5603, a top side 5605, and an open middle area5607. FIG. 56A illustrates the bottom (wound-facing) side 5603 of a 3Dfabric, which may be woven so as to create oblong or ovoid openings 5611extending lengthwise across the fabric. In one embodiment, the oblong orovoid openings 5611 represent or provide an open area of between 10 and45% (or about 10% to about 45%) of the surface area of the bottom layer,more preferably 10% to 30% (or about 10% to about 30%). Here, fibers areknitted (for example by warp knitting) so as to also include theselarger openings or pores that permit bulk transport of wound fluids inaddition to wound fluids carried along the fibers by capillary action ofthe fibers. Apertures that are optionally formed in the distal end ofthe 3D fabric (as illustrated in FIGS. 55D and J) may also aid in thebulk evacuation of wound debris and fluids.

FIG. 56B illustrates the top side 5605 of a 3D fabric that may be usedas described herein. This top side 5605 in one embodiment does not havethe larger ovoid apertures 5611 of the bottom side 5603, but may haveopenings 5613 defined by fibers extending lengthwise and generallytransversely or at an angle across the width of the fabric. Asillustrated, these openings are generally rhombus-shaped. In oneembodiment, these openings 5613 may represent or provide an open areagreater than that of the bottom layer, for example between 30% and 50%(or about 30% and about 50%). Of course, it will be understood that thefabric presented here is a non-limiting example, and different fabricconfigurations and orientations are possible, for example with the topside 5605 being placed downward so as to face the wound and with thebottom side 5603 facing upward.

FIG. 56C illustrates a cross-section of a 3D fabric (the bulb-likeprojections on the vertical fibers in the fabric are an artifact of thecutting process). The vertically extending fibers 5609 may be woven soas to extend through the middle open area 5607 while also beingconnected to the bottom and top layers 5603 and 5605. Preferably, thefibers 5609 present in the open middle layer 5607 will have sufficientstiffness so as to help prevent compression of the fabric. Asillustrated in this figure, and without wishing to be bound by theory,3D fabrics that have been found to perform well will often include alarger open area 5607 in the middle portion that may permit exudates andother fluids to be effectively transported away from a wound site whileunder the application of negative pressure, while more densely-wovenouter layers 5603, 5605 may aid in providing additional tensile strengthand capillary wicking action. For example, the middle layer may includean open volume of greater than 50% (or greater than about 50%).Obviously, the resulting fabric cannot be too thick or composed offibers that are too stiff, as the resulting suction adapter and systemmay not remain sufficiently flexible for comfortable usage with apatient.

It will often be advantageous to tailor the performance characteristicsof the 3D fabric while in use to account for various requirements of thesuction adapter. In particular, the flow rate of exudate through thefabric, for example when under compression, may be simplified byconsidering the porosity of the fabric. In such situations, and againwithout wishing to be bound by theory, the porosity of the fabric, andthus the space that will be available for fluids to travel through, maybe determined in part by the knit pattern of the fibers used in creatingthe 3D fabric, the thickness of the fibers used therein, and theirrespective stiffness and hardness (especially when under compression).Fibers may also be modified by surface properties (the fibers can beflat or textured) and the number of fibers or filaments used in theresulting fabric. Compression resistance may be affected by the choiceof fiber or monofilament used in the vertical axis of the fabric, andgenerally, a stiffer material will improve compression resistance onthis axis. Other materials properties, such as hydrophobicity, may playa role. In some cases, it may be beneficial to treat the fabric to behydrophilic, for example with a hydrophilic polymer, so as to improvewicking of fluids. Preferred embodiments of the 3D fabric used withcertain suction adapters have been found to work well when Baltex®fabric is treated in such a fashion. Other possible treatments mayinclude lipophilic coatings to prevent proteins from adhering andbuilding up during use, which may cause clogging and loss of pressure tothe wound site.

The flow rate through the 3D fabric while under the application ofnegative pressure may be approximated by considering each opening as aseparate orifice plate subject to Bernoulli's principle while underlaminar flow. To simplify calculations, the area of openings for a givenarea of 3D fabric may be used. Thus, the 3D fabric may be optimized toachieve a good balance between factors such as the compressionresistance required and the resulting flow rate under the application ofnegative pressure. Further optimization will also take place with thestiffness and flow rate of the 3D fabric being tailored to applicationin the embodiments described herein. Optimization of the properties anddimensions of the 3D fabric will also preferably take into account abalancing between the flow rate and stiffness required and theconformability of the fabric, as a fabric that is too stiff may not bendappropriately and may also be uncomfortable on the patient. The 3Dfabric should preferably be designed so as to yield when compressedagainst tissue, thereby preventing tissue compression (for exampleagainst bony prominences in the patient) and the discomfort and damage,such as pressure ulcers, that may follow. For example, the dimensions ofthe fabric may be tailored for the ultimate use of the suctionadapter—smaller in the case of distal extremities such as fingers, andlarger for abdominal and burn wounds. A fabric that is too stiff mayalso cause pressure ulcers and other such complications, although it mayfunction acceptably in larger dimensions.

In practice, and as also described previously herein, flow rates throughembodiments of the suction adapter using 3D fabrics are at least 0.08L/min, preferably up to 10 L/min during the application of negativepressure, and should be able to handle fluid exudate drainage of atleast 10 L/day. Some embodiments of the suction adapter may beconfigured to handle much larger wounds, including abdominal wounds, andwhich in some cases may exude at least 0.5 L/hr, or 12 L/day. In moreextreme cases, the pump used (for example, the RENASYS EZ) may be ableto evacuate up to 16 L/min, thereby evacuating a large wound to anegative pressure level of 120 mmHg in less than a minute. The pressuredrop calculated due to the 3D fabric should be minimal, and the level ofnegative pressure measured at a wound site is preferably within 25 mmHgof the pressure level measured at the source of negative pressure.Although the pressure drop increases as the negative pressure appliedincreases (thus rendering the 25 mmHg target more difficult to reach),embodiments of the wound treatment system are preferably able tomaintain this target pressure to at least a negative pressure of 200mmHg. The suction adapter and system are preferably able to functionwithin pressure ranges required for negative pressure, which areestimated to be from around 40 mmHg to 200 mmHg. Pressure ranges greaterthan 200 mmHg are possible, but these may in some circumstances causepatient discomfort. The apparatus may also function at lower pressureranges, such as 20 mmHg, although at such low pressure levels thetherapeutic effects resulting from negative pressure may be diminished,with the device acting more as a drainage device. Preferably,embodiments of a negative pressure treatment system are able to maintainthese target pressures at the wound site within 95% of the time thatnegative pressure is being applied to the wound. In some embodiments,the fabric may comprise several layers of material stacked or layeredover each other, which may in some cases be useful in preventing thechannel 5516 from collapsing under the application of negative pressure.In other embodiments, the fabric used in channel 5516 may be between 1.5mm and 6 mm; more preferably, the fabric may be between 3 mm and 6 mmthick, and may be comprised of either one or several individual layersof fabric. In other embodiments, the channel 5512 may be between 1.2-3mm thick, and preferably thicker than 1.5 mm. Preferably, the 3D fabricis able to withstand a load of at least 5.3 psi with a compression ofnot more than 10% of the fabric's original thickness. Further, the 3Dfabric may also be able to resist compression to less than half of itsoriginal thickness when subjected to a load of 15 psi.

In a preferred embodiment, a 3D fabric may be woven from 100% polyesterusing yarns of 150 and 225 Denier, to yield a fabric weighingapproximately 23 to 25 oz per square yard. In these cases, the fabricmay be approximately 5.8-6.8 mm thick. The bottom portion of the fabricmay also have several openings or pores 5611 similar to thoseillustrated in FIG. 56A, which may be elongated, rectangular or ovoid inshape and oriented with their long axis lengthwise along the fabric. Theopenings 5611 may be arranged in a plurality of rows extendinglengthwise across the fabric, for example 2 to 5 rows, or morepreferably 3 rows as illustrated in FIG. 56A. The openings 5611 may bespaced equidistantly from each other in each of the rows, and may form astaggered pattern from one row to another. In one embodiment, each rowmay have approximately 6-10 openings, more preferably 8 openings, per 2inches (or about 50 mm). Along a given width or transverse dimension ofthe fabric, the transverse rows formed by the openings may have aspacing of approximately 6-10 openings, more preferably 8 openings, per21/8 inches (or about 54 mm). In one embodiment, the openings may have alength of between about 1/16″ to about 1″ lengthwise, and a width ofbetween about 1/32″ and ½″ widthwise. In one example, the openingsmeasure approximately ⅛″ (or about 3.2 mm) lengthwise and 1/32″ (orabout 0.79 mm) across. The 3D fabric in one embodiment may have anoverall length of between about 50 and 100 mm, more preferably about 60mm, a width between about 5 and 15 mm, more preferably about 9 mm, and athickness of about 6 mm.

Embodiments of the systems described herein have been tested and foundto perform satisfactorily. Such testing was performed by constructingsuction adapters from embodiments described herein. The distal ends ofthe suction adapters were then placed over an aperture made onto a drapeplaced over a simulated wound cavity provided with a source of simulatedwound fluid, which was controllable and which can vary the flow rate ofthe wound fluid. The simulated wound cavity was also in some casespacked with foam or some other wound packing material. In some tests,the simulated wound fluid was a 5:1 water to glycerol mix, and in othersfiltered horse serum (available from Oxoid, United Kingdom) was used.The proximal end of the suction adapter was then connected to a sourceof negative pressure, in this case a pump. Flow rate tests and othermeasurements were then conducted at various negative pressure ranges andsimulated exudate flow rates and air leak rates.

FIGS. 57A-B illustrate embodiments of a connector 5704, similar to theconnectors 1504 and 5506 described previously, and which may be used tosecurely connect a source of negative pressure to a channel 5716 of asuction adapter such as the ones described herein. For example, thischannel 5716 may be the upper channel 1512 or, more preferably, thelower channel 1516 illustrated in FIGS. 15A-D, as well as the channels5512 and 5516 in FIGS. 55-56. Generally, such connectors 5704 may beuseful in providing a more secure connection from the source of negativepressure to a negative pressure treatment system. The use of theseconnectors 5704 is optional, and may not be necessary in all embodimentsdescribed herein. In use, a tube 5740 connected to the connector 5704may pull, or other external forces may somehow disengage the connector5704 away from the channel 5716 to which it is attached. In suchsituations, application of negative pressure to the wound may be reducedor stopped. Further means to secure the connector 5704 to the remainderof the system may, as described above, include bonding or attachingother layers of the treatment system, if present, to the connector 5704.For example, in the case of the embodiments described in FIGS. 15A-D,this may include bonding at least one of the layers 1510, 1514, 1518 tothe connector 5704. The connectors 5704 may be designed so as to createa secure connection with a fabric or material used in a channel; when 3Dfabrics or 3D knitted materials are used, some embodiments of theconnector 5704 are configured to engage with or attach to a portion ofthe material or fibers of the material to create a more secureconnection. Preferably, embodiments of the connector 5704 are able towithstand a pulling force of up to 20 kg before disconnection and/orfailure of the connector occurs, preferably such that the connectordisengages from the channel it is connected to. It will be understoodthat other embodiments may be configured to withstand a lower pullingforce, and may be tailored to release so to prevent injury to a patient(for example, constriction of the suction adapter and/or drainage tubesaround a limb).

FIGS. 57A-B illustrate an embodiment of the connector 5704 a comprisingtwo or more projections 5752 extending distally lengthwise from thepreferably cylindrical main body of the connector 5704 a. The main bodyalso comprises a central channel 5755 extending lengthwise through themain body of the connector 5704 a. The projections 5752 may additionallycomprise one or more barbs 5754 attached thereto. Preferably, thesebarbs 5754 are angled proximally so as to act as anchors when pushed orinserted into the channel 5716. When the channel 5716 is a 3D fabric orknitted material, the barbs 5754 are configured to engage to the fiberstherein, creating a more secure connection. At the proximal end of theconnector 5704 a, a lip 5756, which may be provided in a frustoconicalform, may also be provided for connection to a tube 5740. The tube 5740may be connected to the connector 5704 a (as well as the otherconnectors described herein) for example by press-fitting, althoughother connections means are possible. The tube 5740 may be the same astube 5507 in FIG. 55J, or it may be any other tube used to provide fluidcommunication with a source of negative pressure. It will also beappreciated that the features of these connectors, particularly at thedistal ends, can be incorporated onto the ends of tubes used tocommunicate negative pressure, such that those tubes can be directlyconnected to the suction adapter system.

While the above detailed description has shown, described, and pointedout novel features as applied to various embodiments, it will beunderstood that various omissions, substitutions, and changes in theform and details of the device or process illustrated may be madewithout departing from the spirit of the disclosure. Additionally, thevarious features and processes described above may be used independentlyof one another, or may be combined in various ways. All possiblecombinations and subcombinations are intended to fall within the scopeof this disclosure. Many of the embodiments described above includesimilar components, and as such, these similar components can beinterchanged in different embodiments.

Although the invention has been disclosed in the context of certainembodiments and examples, it will be understood by those skilled in theart that the invention extends beyond the specifically disclosedembodiments to other alternative embodiments and/or uses and obviousmodifications and equivalents thereof. Accordingly, the invention is notintended to be limited by the specific disclosures of preferredembodiments herein.

What is claimed is:
 1. A negative pressure wound therapy dressingcomprising a drainage tube, wherein the drainage tube comprises achannel knitted from a monofilament yarn, wherein an impermeable sheathsurrounds the knitted channel, wherein the impermeable sheath comprisesa distal end configured to be attached to a cover layer of the negativepressure wound therapy dressing, and wherein the knitted channel is influid communication with a connector comprising a proximal end and adistal end, wherein the distal end of the connector extends into aproximal end of the knitted channel.
 2. The negative pressure woundtherapy dressing according to claim 1, wherein the monofilament yarn isa polyester or polyamide monofilament yarn.
 3. The negative pressurewound therapy dressing according to claim 1, wherein the impermeablesheath comprises one or more sheets of an impermeable material.
 4. Thenegative pressure wound therapy dressing according to claim 3, whereinthe knitted channel is sandwiched between two sheets of an impermeablematerial.
 5. The negative pressure wound therapy dressing according toclaim 4, wherein a length of the connector rests between the two sheetsforming a fluid-tight seal with both of the two layers.
 6. The negativepressure wound therapy dressing according to claim 1, wherein theimpermeable sheath is adhered to the knitted channel.
 7. The negativepressure wound therapy dressing according to claim 1, wherein theimpermeable sheath is a polyurethane sheath.
 8. The negative pressurewound therapy dressing according to claim 1, wherein one end of thedrainage tube forms an integral tab by which the drainage tube can beattached to the cover layer.
 9. The negative pressure wound therapydressing according to claim 1, wherein one end of the drainage tube isadapted for connection to a source of negative pressure.
 10. A method oftreating a wound comprising the steps of (a) applying the negativepressure wound therapy dressing according to claim 1 to a wound and (b)applying a negative pressure to the dressing via the drainage tube. 11.A knitted channel for use in medical applications wherein the channel isknitted from monofilament yarn, wherein an impermeable sheath surroundsthe knitted channel, wherein the impermeable sheath comprises two sheetsof an impermeable material and the knitted channel is sandwiched betweenthe two sheets of the impermeable material, wherein the impermeablesheath comprises a distal end configured to be attached to a negativepressure wound therapy dressing, wherein the distal end of a lower ofthe two sheets comprises at least one aperture configured to align withat least one aperture of the negative pressure wound therapy dressing,and wherein the at least one aperture of the distal end of the lower ofthe two sheets and the at least aperture of the negative pressure woundtherapy dressing are configured to be positioned over a wound.
 12. Thechannel according to claim 11, wherein the monofilament yarn is apolyester or polyamide monofilament yarn.
 13. The channel according toclaim 11, wherein the impermeable sheath is adhered to the knittedchannel.
 14. The channel according to claim 11, wherein the impermeablesheath is a polyurethane sheath.
 15. The channel according to claim 11,wherein the two sheets of the impermeable material at the distal end ofthe impermeable sheath each has an enlarged distal end.